The scale of the problem the researchers are targeting is enormous. Osteoarthritis affected approximately 595 million people in 2020, roughly 7.6 percent of the global population, and case numbers are projected to rise substantially by 2050 as populations age. One in eight adults over the age of 60 lives with knee osteoarthritis, making it the most common form of arthritis and a leading cause of disability. Although the disease was long viewed as simple wear-and-tear of cartilage, it is now recognised as a whole-joint condition involving synovial inflammation, subchondral bone remodelling, and inflammatory signalling across multiple tissues, with low-grade inflammation playing a driving role in disease progression.

Current treatments struggle to keep pace with that biology. Intra-articular corticosteroid injections are recommended in clinical guidelines and can reduce swelling and pain, but their benefits typically fade within weeks, forcing patients back for repeated injections that carry risks of swelling, infection, and septic arthritis. Hyaluronic acid injections restore lubrication and exert their own anti-inflammatory effects, yet the molecule persists in the joint for only about a day. Intra-articularly injected steroids typically remain in the knee for just one to four hours before being cleared. Oral anti-inflammatory drugs carry their own burdens, with long-term NSAID use linked to gastrointestinal, renal, and cardiovascular adverse events, particularly in older adults.

The Irish team, led by Jinxin Zhang and David Brayden at University College Dublin with collaborators at the Royal College of Surgeons in Ireland and the National Orthopaedics Hospital Cappagh, designed a dual-function carrier to address both problems at once. The core of each particle is a solid lipid nanoparticle built from tristearin, a stable, ordered triglyceride that can trap lipophilic drugs in its matrix. A small amount of the cationic lipid DOTAP gives the particle surface a positive charge, while DMG-PEG 2000 provides a steric stabilising layer. Wrapped around that positively charged core is a shell of hyaluronic acid, whose negatively charged carboxyl groups bind electrostatically to the particle surface.

Manufacturing was a central challenge, and the researchers turned to microfluidics to solve it. Conventional hot homogenisation, in which molten lipid is sheared into droplets at high speed, produced particles of 240 to 390 nanometres with variable size distributions and modest drug encapsulation. By contrast, the NanoAssemblr Ignite system, which rapidly splits and merges streams of organic and aqueous phases to achieve uniform mixing, yielded monodisperse particles of roughly 90 nanometres with an encapsulation efficiency of 88 percent and a drug loading of 6 percent by weight—outperforming even the commercial liposomal dexamethasone palmitate formulation Lipotalon, which achieved only 4 percent loading before being discontinued. The same microfluidic technology underpins the mRNA COVID-19 vaccines, and its scalability is a key advantage for translating laboratory formulations toward clinical use.

Characterisation confirmed that the hyaluronic acid coating had attached as intended. Infrared spectroscopy revealed the signature carboxylate and hydroxyl peaks of the polymer on the coated particles, and enzyme-linked immunoassays quantified roughly 0.45 milligrams of hyaluronic acid per gram of nanoparticles. The coating also transformed the particle surface, shifting the zeta potential from a strongly positive +30.8 millivolts to a negative −17.3 millivolts, and it improved colloidal stability: over four weeks of storage, coated particles held their size and uniformity while uncoated controls swelled and became more heterogeneous. Notably, the 90-nanometre final size sits near the mesh size of the dense superficial cartilage matrix, estimated at 50 to 60 nanometres, which governs how deeply particles can penetrate joint tissue.

Drug release studies revealed a biphasic profile that the coating further moderated. In buffered saline at body temperature, both coated and uncoated particles released an initial burst of drug within the first eight hours, followed by a slower, diffusion-dominated phase. By 120 hours, uncoated particles had released about 96 percent of their payload, while coated particles reached about 94 percent—but at every intermediate time point the coated formulation released less drug, showing that the hyaluronic acid shell acts as an additional diffusional barrier without preventing eventual release. In mouse plasma, enzymes cleaved the palmitate ester of the prodrug, converting dexamethasone palmitate into active dexamethasone, which accumulated steadily over 72 hours. This enzymatic activation is the chemical trick that makes the prodrug strategy work: the hydrophobic palmitate chain anchors the drug in the lipid matrix, preventing premature leakage, while esterases in the joint gradually liberate the active steroid.

The biological experiments provided the study’s most striking results. When human THP-1 monocytes were stimulated with bacterial lipopolysaccharide to trigger inflammation, both coated and uncoated nanoparticles suppressed secretion of prostaglandin E2, a key inflammatory mediator linked to pain signalling, cartilage catabolism, and bone remodelling in osteoarthritis. But the hyaluronic acid-coated particles outperformed their uncoated counterparts at every concentration tested. The same pattern held in primary chondrocytes derived from actual osteoarthritis patients, where coated particles again suppressed prostaglandin E2 more effectively while maintaining cell viability above 95 percent. Confocal microscopy confirmed that fluorescently labelled nanoparticles were internalised by the patient-derived chondrocytes within hours, with fluorescence distributed throughout the cytoplasm around the nuclei.

The enhanced efficacy of the coated particles likely reflects the biology of CD44, the principal cell-surface receptor for hyaluronic acid. CD44 is overexpressed on activated macrophages, synoviocytes, and chondrocytes within inflamed joint tissue, and hyaluronic acid functionalisation has previously been shown to boost cellular uptake and therapeutic effect in rheumatoid arthritis models and in oncology settings. The authors note that the coating contributes actively to therapeutic efficacy rather than serving merely as a stabiliser, extending a strategy validated in other inflammatory diseases into primary osteoarthritic cells for the first time. Importantly, the cationic lipid DOTAP, which can be toxic at high concentrations, was shielded by the PEG and hyaluronic acid layers, and neither free drug nor nanoparticles harmed the cells under test conditions.

The researchers caution that these are in vitro findings, and that the 72-hour plasma release profile reflects enzymatic activation under sink conditions rather than joint retention in a living animal. In the synovial environment, restricted diffusion through viscous fluid, limited lymphatic clearance of particles around 90 nanometres, and binding of the hyaluronic acid shell to cartilage components via CD44 could all prolong drug exposure well beyond what the laboratory assays suggest. The team’s next step is in vivo evaluation in clinically relevant animal models that replicate both cartilage and subchondral bone pathology. If those studies succeed, a single injection that merges the anti-inflammatory power of a corticosteroid with the joint-protecting biology of hyaluronic acid could reduce the frequency of painful repeat injections for millions of patients whose knees currently demand them every few weeks.

Subject of Research: Hyaluronic acid-coated solid lipid nanoparticles for intra-articular delivery of dexamethasone palmitate in knee osteoarthritis

Article Title: Synthesis, characterisation, and in vitro assessment of hyaluronic acid-coated solid lipid nanoparticles entrapping dexamethasone palmitate designed for intra-articular administration

Article References: Zhang, J., Khandelia, R., Hogg, B., Bahlool, A. Z., Hodgkinson, T., Cryan, S.-A., O’Byrne, J., & Brayden, D. J. (2026). Synthesis, characterisation, and in vitro assessment of hyaluronic acid-coated solid lipid nanoparticles entrapping dexamethasone palmitate designed for intra-articular administration. Frontiers in Drug Delivery, 6, Article 1809275. https://doi.org/10.3389/fddev.2026.1809275

Image Credits: AI Generated

DOI: 10.3389/fddev.2026.1809275

Keywords: osteoarthritis, solid lipid nanoparticles, hyaluronic acid, dexamethasone palmitate, intra-articular drug delivery, microfluidics, glucocorticoids, prostaglandin E2, chondrocytes, CD44, drug release, nanomedicine

Starch is one of the most abundant biopolymers on Earth, accumulated in granules within cereals, tubers, roots, and seeds. Each granule is built from two polysaccharides: amylose, a predominantly linear alpha-(1–4) linked glucan that tends to retrograde and form strong films, and amylopectin, a highly branched molecule that produces softer gels and weaker films. The ratio of these two components, along with the degree of crystallinity imparted by amylopectin’s short branches, determines how a given starch behaves under heat, pressure, and hydration. Native starches, however, suffer from well-known limitations, including poor thermal stability, syneresis, and retrogradation, which restrict their usefulness in demanding applications such as pharmaceutical formulations.

To overcome these weaknesses, the research team turned to chemical modification, specifically esterification with malonic acid, a dicarboxylic acid that can bridge adjacent starch chains through ester bonds. The process was deliberately designed to be environmentally benign: the reaction was carried out in water at 90 degrees Celsius, avoiding the organic solvents that typify conventional starch modification routes. Formaldehyde was used as a co-crosslinking agent, a detail the authors themselves flag as a limitation, noting that future work should confirm its complete removal and explore aldehyde-free alternatives. Nevertheless, the predominantly aqueous approach represents a meaningful step toward greener excipient manufacturing.

The chemical evidence for successful modification was compelling. Attenuated total reflectance Fourier transform infrared spectroscopy revealed a new carbonyl stretching peak near 1720 wavenumbers, the signature of ester bonds linking malonate groups to the starch backbone. Titrimetric analysis established a degree of substitution of 0.081 plus or minus 0.009, meaning roughly one in twelve anhydroglucose units carried a malonate substituent. While modest compared with some other carboxylic-acid-modified starches, this substitution level proved sufficient to disrupt the native hydrogen-bonding network and limit chain mobility, with measurable downstream consequences for water uptake, matrix integrity, and drug release.

X-ray diffraction provided structural confirmation of this disruption. Native Gorakhnath-509 starch displayed the characteristic A-type diffraction pattern typical of cereal starches, with reflections at 15, 17, 18, and 23 degrees two-theta. After modification, the intensities of these peaks were visibly attenuated, indicating a qualitative loss of the native semicrystalline order. The authors are careful to note that because the starch was pregelatinized before chemical treatment, thermal processing itself may have contributed to the loss of crystallinity, and a gelatinized but chemically unmodified control was not included in the experimental design. This is an honest caveat that tempers, but does not eliminate, the structural interpretation.

The functional payoff emerged most clearly in the tablet formulations. Using diclofenac sodium as a model drug, the team compressed tablets containing 1, 3, and 5 percent by weight of either native or modified starch as the binder. At the lowest binder level, the modified starch delivered harder tablets, 16.5 plus or minus 0.46 newtons versus 15.66 plus or minus 0.57 newtons for native starch, a statistically significant difference confirmed by one-way ANOVA with Tukey’s post hoc test. Friability, the tendency of tablets to crumble during handling, fell to 0.15 percent for the modified formulation compared with 0.37 percent for its native counterpart, and all six formulations remained comfortably below the pharmacopoeial acceptance threshold of 1.0 percent.

Intriguingly, the hardness advantage did not persist at higher binder concentrations. At 3 and 5 percent binder levels, the modified starch formulations were actually softer than their native counterparts, a concentration-dependent reversal the authors attribute, tentatively, to differences in the deformation and compaction behavior of the esterified matrix at higher loadings. The underlying mechanism was not directly probed in this study, but the finding underscores a broader lesson in excipient science: chemical modification does not produce uniform improvement, and formulation scientists must map performance across the full range of use concentrations before drawing conclusions about superiority.

The dissolution results may prove to be the study’s most consequential contribution. At every binder concentration, tablets containing modified starch released diclofenac sodium faster and more completely than those bound with native starch. The most striking contrast appeared at the 3 percent binder level, where the modified formulation achieved approximately 96 percent cumulative release compared with 77 percent for the native starch version. Kinetic modeling with the DDSolver software showed that the Korsmeyer-Peppas model provided the best fit across all six formulations, with correlation coefficients between 0.9897 and 0.9997. Release exponents greater than 1.0 pointed to Super Case-II transport, a mechanism in which drug release is governed not by simple Fickian diffusion but by the coupled processes of polymer swelling, chain relaxation, and matrix erosion.

This transport mechanism fits neatly with the swelling observations. When tablets were placed on agar gel plates, the modified starch formulations swelled more dramatically than their native counterparts, consistent with the enhanced water uptake expected from a more amorphous, esterified matrix. The combination of high release exponents, pronounced swelling, and XRD evidence for a lightly crosslinked, less crystalline structure paints a coherent mechanistic picture: water penetrates the tablet, the modified starch matrix hydrates and relaxes, and the gel layer gradually erodes, releasing drug in a sustained and predictable fashion. For a biodegradable, rice-derived excipient, this is precisely the kind of controlled-release behavior that formulators seek.

The study is not without limitations, and the authors acknowledge them candidly. The absence of scanning electron microscopy leaves the morphological changes of the modified starch unvisualized, the thermal confound in the modification process complicates attribution, and formal life-cycle assessment would be needed before making sweeping environmental claims. Yet the core achievement stands: a high-amylose rice starch from a regional cultivar, transformed through a largely solvent-free reaction into a pharmaceutical binder that improves tablet integrity at low concentrations and enables sustained, Super Case-II drug release. As the industry searches for biocompatible, biodegradable excipients, this work suggests that the answer may be growing in the paddy fields of the eastern Himalayas, waiting only for the right chemistry to unlock its potential.

Subject of Research: Chemical modification of Gorakhnath-509 rice starch with malonic acid for use as a pharmaceutical tablet binder and controlled-release excipient

Article Title: Structural and functional evaluation of modified native rice starch for tablet formulations

Article References: Chakraborty, P., Chantel, A., Shivam, S., Chakraborty, D. D., & Sen, A. (2026). Structural and functional evaluation of modified native rice starch for tablet formulations. Discover Chemistry, 3(1), Article 552. https://doi.org/10.1007/s44371-026-00953-6

Image Credits: AI Generated

DOI: 10.1007/s44371-026-00953-6

Keywords: rice starch, malonic acid, crosslinking, tablet binder, diclofenac sodium, drug release, Korsmeyer-Peppas, green chemistry, pharmaceutical excipient, X-ray diffraction, degree of substitution, biodegradable polymer

The design tackles a fundamental tension in wound care. Photothermal therapy, in which light-absorbing nanoparticles heat tissue enough to rupture bacterial membranes, is a powerful antibacterial tool, but the same heat can destroy the delicate growth factors and proteins needed for tissue repair. The researchers solved this by building a material in which heat is not a side effect but a control signal: it triggers the hydrogel to shrink, and that shrinkage itself becomes the mechanism that times and delivers the drugs.

The hydrogel backbone is a copolymer network of gelatin methacryloyl (GelMA), N-isopropylacrylamide (NIPAM), and N-acryloyl glycinamide (NAGA), crosslinked in seconds by 395 nm ultraviolet light. GelMA contributes cell-adhesive motifs that bind integrin receptors on fibroblasts and endothelial cells, supporting proliferation and new blood vessel growth. NAGA was added to counter the brittleness of GelMA; through dense hydrogen bonding it toughens the network, and its polymer form exhibits an upper critical solution temperature that complements the lower critical solution temperature of roughly 32 degrees Celsius displayed by PNIPAM. This dual thermoresponsive architecture gives the material finer control over contraction than single-transition systems.

Embedded in this network are the true workhorses: core-shell nanoparticles made of magnesium coated with polydopamine and conjugated with the fluoroquinolone antibiotic levofloxacin. X-ray photoelectron spectroscopy revealed a striking chemical detail, an interfacial magnesium-fluorine bond that anchors the drug to the particle surface. That bond is acid-sensitive, which matters because infected wounds are typically more acidic than healthy tissue. In the acidic, irradiated environment of an early infection, polydopamine degrades and levofloxacin pours out to halt bacterial DNA replication; as conditions later neutralize, release slows to a sustained trickle of magnesium ions suited to regeneration rather than killing.

The light-triggered mechanics are equally precise. Under 808 nm near-infrared irradiation at 2.0 watts per square centimeter, the polydopamine nanoparticles heat the hydrogel to roughly 45 to 48 degrees Celsius within minutes, pushing it past its phase-transition temperature of about 34 degrees. The network collapses, shrinking in volume by more than 35 percent, and this contraction mechanically drives out the payload. The team quantified the link rigorously: Pearson correlation analysis showed that early-stage release increments of both levofloxacin and magnesium tracked volume shrinkage with coefficients of determination above 0.95. At body temperature without light, passive leakage stayed below 5 percent over 24 hours, meaning the dressing keeps its cargo locked until commanded otherwise.

That command proved devastating to bacteria. Against Escherichia coli and Staphylococcus aureus, the illuminated composite hydrogel reduced viable colony counts by factors of 332 and 212 respectively, far outperforming free antibiotic or heat alone. Scanning electron micrographs showed collapsed membranes and leaked intracellular contents, evidence of the dual mechanism in which photothermal heating disrupts bacterial envelopes while released levofloxacin blocks replication. Crystal violet assays revealed the same hierarchy against biofilms, the slimy bacterial fortresses that chronically resist both immune clearance and antibiotics. The authors note that combining physical and chemical killing may also reduce the selection pressure that drives antibiotic resistance, allowing effective treatment at lower drug doses.

Beyond sterilization, the material actively reshapes the wound’s immunological and vascular landscape. Sustained magnesium release pushed inflammatory M1 macrophages toward the healing-associated M2 phenotype, an effect amplified by mild photothermal stimulation, while polydopamine mopped up the reactive oxygen species that would otherwise sabotage angiogenic signaling. Under oxidative stress mimicking a pathological wound bed, endothelial cells treated with the illuminated hydrogel showed near-complete ROS clearance, robust proliferation, and markedly enhanced tube formation and migration. Macrophage migration reached 86.7 percent within 24 hours, the highest of any tested condition, supporting a swift transition from inflammation to tissue building.

The in vivo results were the most striking. In rats with Staphylococcus aureus-infected full-thickness skin defects, the precursor solution was injected into the wound bed and gelled in place under brief ultraviolet exposure, then irradiated on three consecutive days. Thermal imaging confirmed the hydrogel reached approximately 47 degrees at the wound surface, while histology and TUNEL staining showed no thermal injury to the surrounding tissue. Bacterial burden in the wounds fell roughly 27-fold compared with untreated controls. Wound area shrank by 57 percent at day 3, 73 percent at day 7, and 98.4 percent by day 14, with the hydrogel degrading almost completely in step with tissue regrowth.

Microscopic analysis of healed tissue told the deeper story of why the treated wounds fared better. The MPLG group showed continuous epidermis, the lowest scar index, and well-aligned, densely packed collagen fibers. Immunofluorescence revealed a shift from M1 to M2 macrophage markers, elevated CD31 signaling new blood vessel formation, increased Ki67-driven proliferation, and a maturing collagen profile in which strong type I collagen replaced the provisional type III network. Blood counts, serum chemistry, hemolysis rates, and organ histology all remained normal, indicating the material and its light treatment are well tolerated systemically.

The authors are candid about the road to the clinic. Deep ultraviolet gelation penetrates less than a centimeter of tissue, a limitation for irregular or heavily exuding wounds, and the long-term safety of repeated near-infrared heating in diabetic or ischemic wounds remains unproven. Scaling the multistep nanoparticle synthesis under good manufacturing practice will also demand careful batch control. Still, the modular concept, a dressing that physically pulls wound edges together while releasing the right drug at the right moment, could extend beyond skin to burns and diabetic ulcers, marking a shift from dressings that merely protect wounds to materials that actively run the healing program.

Subject of Research: A near-infrared-responsive contractile hydrogel with core-shell nanoparticles for programmed antibacterial and pro-angiogenic wound healing

Article Title: Contractile hydrogel with NIR-induced spatiotemporally programmed release from core-shell nanoparticles for integrated antibacterial and pro-angiogenic healing

Article References: Zhang, M. J., Song, J., Song, X., Zhang, A., XI, H., & Xin, L. (2026). Contractile hydrogel with NIR-induced spatiotemporally programmed release from core-shell nanoparticles for integrated antibacterial and pro-angiogenic healing. Materials Today Bio, 41, Article 103713. https://doi.org/10.1016/j.mtbio.2026.103713

Image Credits: AI Generated

DOI: 10.1016/j.mtbio.2026.103713

Keywords: hydrogel, wound healing, photothermal therapy, near-infrared, levofloxacin, polydopamine, magnesium ions, antibacterial, biofilm, angiogenesis, macrophage polarization, drug release

The clinical problem the team set out to address is formidable. Deep burns destroy the skin’s role in thermal insulation, fluid balance, and microbial defense, leaving patients vulnerable to dehydration, infection, and inflammatory cascades that can progress to sepsis or multi-organ failure. Impaired vascularization in burn tissue reduces the effectiveness of systemic antibiotics, and prolonged antibiotic use has fueled resistant strains such as methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. Conventional dressings like gauze and petroleum-based products act as passive barriers, and their tendency to adhere to wound beds can tear away healing tissue during dressing changes. The researchers argue that next-generation dressings must actively stabilize the wound microenvironment, modulate inflammation, counter biofilm-associated infection, and support tissue regeneration simultaneously.

Hydrogels, three-dimensional networks of hydrophilic polymers, are well suited to this challenge. Their high water content maintains the moist environment that promotes epithelialization and fibroblast proliferation, while their non-adhesive character minimizes damage during dressing changes. They also provide an intrinsic cooling effect that helps relieve pain and local inflammation. Crucially, hydrogels can be functionalized with bioactive compounds and nanomaterials, enabling localized, controlled delivery of therapeutic agents directly to the wound site. Previous studies have shown collagen-based hydrogels promoting angiogenesis, chitosan hydrogels loaded with gentamicin fighting S. aureus and E. coli while supporting collagen synthesis, and curcumin-loaded chitosan hydrogels reducing oxidative stress in rat burn models. The Wichita team extended this concept by combining multiple active agents in a single matrix.

Each ingredient in the new formulations was chosen for a complementary biological role. Selenium, supplied as sodium selenite, is a critical micronutrient with antioxidant and anti-inflammatory properties that enhance vascularization and reduce oxidative stress. Silver and copper nanopowders serve as broad-spectrum antimicrobial agents that inhibit bacterial proliferation and biofilm formation. Silver sulfadiazine, a clinically established burn treatment, was incorporated as a benchmark for infection-control performance. Natural compounds rounded out the design: almond oil supports skin regeneration and hydration, neem oil shows activity against burn wound pathogens, propolis contributes antimicrobial and tissue-regenerative effects, and vitamins A and C support collagen synthesis, angiogenesis, and epithelial repair. The base matrix combined chitosan, gelatin, and acetic acid, with polyethylene glycol used in control formulations.

Preparation followed carefully controlled protocols. Chitosan was dissolved in water at 60 degrees Celsius under continuous stirring, bioactive additives were dissolved separately and dispersed into the solution, and acetic acid was added dropwise to trigger gelation into a semi-solid state. After 24 hours of homogenization, the hydrogels were cured in an oven at 45 degrees Celsius and refrigerated to stabilize their structure. Gelatin-based variants and formulations containing natural substances, silver or copper nanopowders, silver sulfadiazine, or a traditional Turkish ointment were prepared with parallel procedures, and control hydrogels using acetic acid or gelatin with polyethylene glycol provided baselines for comparison.

Structural characterization relied on three complementary techniques. Fourier-transform infrared spectroscopy revealed broad absorption bands between 3500 and 3200 reciprocal centimeters corresponding to amine and hydroxyl stretching, confirming the hydrogen bonding that underpins water retention. Peaks near 1630 to 1641 reciprocal centimeters indicated carbonyl and alkene groups associated with cross-linked polymeric networks, with the strongest signals in the selenium-acetic acid formulations, pointing to higher cross-linking density. Thermogravimetric analysis identified four distinct phases of weight loss, from evaporation of loosely bound water below 70 degrees Celsius to complete degradation above 400 degrees, and showed that selenium-enriched and oil-containing hydrogels released moisture more slowly and left greater residual mass, indicating enhanced thermal stability. X-ray diffraction confirmed semi-crystalline gelatin peaks near 20 degrees and the face-centered cubic signatures of silver and copper, verifying uniform nanoparticle integration.

The biological results were the study’s headline finding. Using the methyl thiazolyl tetrazolium assay on 3T3 fibroblast cells, with live/dead staining as confirmation, the team found that all hydrogels were non-toxic and supported cell adhesion and proliferation over five days of culture. The selenium-acetic acid hydrogels stood out dramatically: the formulation containing 1 gram of selenium reached approximately 160 percent cell viability relative to the control, with the 0.6 gram variant close behind. The researchers attribute this to the mildly acidic microenvironment created by acetic acid, which fosters fibroblast proliferation and migration, enhances nutrient diffusion, and increases cross-linking density to produce a mechanically stable, hydrated scaffold for cellular attachment. By contrast, the silver-gelatin and copper-gelatin hydrogels maintained viabilities of roughly 80 and 70 percent respectively, an acceptable trade-off given their antimicrobial function.

Functional testing reinforced the picture of a well-balanced material system. Every formulation retained moisture content of roughly 90 percent, the level needed to keep a wound bed hydrated without desiccation. Swelling tests at physiological 37 degrees Celsius showed large but stable water uptake of approximately 870 to 1005 percent, within the range considered optimal for high-quality hydrogels, with copper-infused samples swelling the most due to additional ionic and hydrogen-bonding sites. Emulsion-based drug release tests over 14 days demonstrated sustained, cumulative release consistent with Fickian diffusion through the hydrated matrix, with the selenium-acetic acid formulations exceeding 60 percent release in later cycles and silver-containing gels surpassing 80 percent. The copper-gelatin hydrogel released more slowly, below 40 percent in the second cycle, but the authors note that even low concentrations of copper ions deliver significant antibacterial effects. pH testing showed the formulations span roughly 4 to 9, with the acidic selenium-acetic acid gels favoring fibroblast activity and microbial inhibition, the alkaline selenium-gelatin gels suppressing bacterial colonization, and the near-neutral metal-infused gels offering versatile biocompatibility.

The authors are candid about the study’s limits. Burn-specific performance criteria, including antimicrobial testing against burn-relevant pathogens such as Pseudomonas aeruginosa and Staphylococcus aureus, and in vivo evaluation, were not included, and future work will validate the formulations in realistic burn models. Nonetheless, the comparative analysis clearly identifies the selenium-acetic acid hydrogels, particularly the 0.6 and 1.0 gram selenium variants, as lead candidates that combine biocompatibility, moisture management, and controlled swelling, while the silver and copper gelatin systems appear suited to infection-prone contexts. The team also points toward scalable manufacturing routes, including 3D printing and bioprinting, and toward tailoring ionic content and bioinspired additives to lift the viability of the metal-containing formulations. If subsequent animal and clinical studies confirm these in vitro results, selenium-enriched multifunctional hydrogels could move burn wound care a significant step beyond passive protection toward dressings that actively participate in regeneration.

Subject of Research: Multifunctional biocompatible hydrogels for burn wound healing

Article Title: Design and development of advanced biocompatible hydrogels for burn wound healing applications

Article References: Paramshetty, M., Khan, Z., Lokesh, S., Parmar, C., Subeshan, B., Yang, S.-Y., & Asmatulu, E. (2025). Design and development of advanced biocompatible hydrogels for burn wound healing applications. Journal of Materials Science: Polymers, 1(1), Article 4. https://doi.org/10.1007/s44493-025-00003-0

Image Credits: AI Generated

DOI: 10.1007/s44493-025-00003-0

Keywords: hydrogels, burn wound healing, selenium, gelatin, chitosan, silver nanoparticles, copper nanoparticles, biocompatibility, drug release, wound dressing, cytotoxicity, biomaterials

The coating, dubbed Ag-Zeo by the team, begins with an unlikely raw material: metakaolin derived from halloysite clay nanotubes, a natural aluminosilicate precursor. Conventional ZSM-5 synthesis relies on organic structure-directing agents such as tetrapropylammonium hydroxide, chemicals that are expensive and environmentally unfriendly. By substituting metakaolin, Ludox silica, silver nitrate and a small amount of ZSM-5 seed crystals, the researchers avoided organic templates entirely. The polished steel coupons were cleaned, aged in the zeolite sol for 48 hours, and then crystallized in a high-pressure reactor at 175 degrees Celsius for two days, allowing zeolite crystals to nucleate and grow directly on the metal surface without any binder.

Characterization confirmed that the coating is the real thing. X-ray diffraction revealed the hallmark reflections of the MFI-type ZSM-5 framework, including the intense peak near 23 degrees two-theta, alongside weaker peaks at 38.1 and 44.8 degrees corresponding to face-centered cubic metallic silver. Nitrogen adsorption measurements showed a Type I isotherm typical of microporous materials, with an exceptionally high BET surface area of about 474 square meters per gram, a pore volume of 0.26 cubic centimeters per gram and an average pore diameter of 2.24 nanometers. Scanning and transmission electron microscopy captured the classic coffin-shaped micron-sized ZSM-5 crystals, roughly 1.21 micrometers across, deposited as a thin, homogeneous film of one to five percent by weight on the steel.

Perhaps the most important structural finding is that silver was incorporated into the zeolite framework rather than simply sprinkled on top. Diffuse reflectance ultraviolet-visible spectroscopy identified three distinct silver species: isolated Ag-plus ions absorbing near 210 nanometers, sub-nanometer silver clusters near 290 nanometers, and metallic Ag-zero nanoparticles showing a surface plasmon band at 418 nanometers. Fourier-transform infrared spectroscopy showed the preserved five-membered ring vibration at about 545 wavenumbers, while shifts in the silicon-oxygen and aluminum-oxygen stretching region between 970 and 1220 wavenumbers pointed to genuine isomorphous substitution. Energy-dispersive X-ray mapping confirmed silver at 1.03 percent by weight, uniformly distributed alongside silicon, aluminum, oxygen and sodium throughout the crystals.

On the coated implant, elemental mapping told an equally encouraging story. Signals from iron, chromium and nickel revealed the underlying alloy, while silver, silicon, oxygen and aluminum confirmed a continuous zeolite layer above it. Because the coating is thin, the electron beam still interacts with the substrate, indicating intimate contact between the two. The researchers argue that this uniform integration matters biologically: silver locked into the framework leaches slowly and evenly, avoiding the concentration spikes that plague surface-deposited nanoparticles, while the microporous architecture can wick up biological fluids and improve interactions between the implant and surrounding tissue.

Corrosion testing in a brutal acidic chloride bath, one molar sodium chloride at pH 1.0, showed the coating earning its keep. Bare stainless steel started with a corrosion current density of 0.014 amperes per square centimeter, which climbed to 0.046 within days as chloride ions attacked the passive chromium oxide film. The Ag-Zeo coated samples moved in the opposite direction, with corrosion current falling from 0.03 to 0.021 amperes per square centimeter over five days of immersion, a sign that the coating-substrate interface was stabilizing rather than degrading. Electrochemical impedance spectroscopy reinforced the picture, showing larger semicircles and higher charge-transfer resistance for coated samples, consistent with a barrier that limits ion diffusion to the metal.

The drug delivery results may be the most clinically provocative. Cisplatin, a platinum-based chemotherapy used against osteosarcoma and other cancers, was loaded into the zeolite with an encapsulation efficiency of 88 percent and a loading capacity of 4.4 percent. When the loaded coating was tested across a pH gradient, it behaved like a smart material. At pH 5.6, which mimics the acidic microenvironment of bone tumors, cumulative cisplatin release climbed steadily to about 15 percent over 72 hours. At physiological pH 7.4, release was slower, reaching only about 10 percent in the same period. Crucially, the profile showed gradual, sustained liberation rather than the dangerous burst release common to many polymer carriers, a behavior the team attributes to host-guest interactions inside the zeolite channels and to a synergistic effect between silver and the platinum complex.

Antifungal performance rounded out the platform’s credentials. Implant-associated Candida albicans infections are notoriously difficult to treat because the fungus builds resilient biofilms that resist azoles, polyenes and other standard drugs. In adhesion assays using Candida albicans ATCC 14053, surfaces treated with Ag-Zeo at 16 milligrams per milliliter showed dramatically fewer adherent, viable fungal cells than untreated surfaces or surfaces treated with zeolite alone, which performed no better than the control. That comparison isolates silver as the active agent, delivered steadily from its zeolite host. The authors point to the established mechanisms of silver action, including reactive oxygen species generation, oxidative and nitrosative stress, membrane disruption and interference with microbial proteins and DNA, all sustained by the controlled ion release that the framework provides.

Taken together, the study sketches a next-generation implant surface that is simultaneously protective, therapeutic and antimicrobial, all from a clay-derived, template-free synthesis that the researchers describe as a sustainable strategy for implant coating technology. The work remains at the laboratory stage, and questions of long-term biocompatibility, mechanical wear and silver dosing in living patients will need to be answered before clinical translation. But the concept, a single green coating that resists corrosion, fights fungal colonization and dispenses chemotherapy on demand in response to tumor acidity, offers a compelling glimpse of where biomaterials engineering is heading: away from passive hardware and toward implants that actively participate in their own defense and in the treatment of the diseases that put them there.

Subject of Research: A green-synthesized silver-integrated ZSM-5 zeolite coating on AISI 316 L stainless steel implants for corrosion resistance, controlled cisplatin delivery and antifungal activity

Article Title: Sustainable silver-integrated ZSM-5 coating on AISI 316 L implants: a multifunctional platform for controlled cisplatin delivery and antifungal activity

Article References: Ravinayagam, V., Cevik, E., Tamilvanan, M., Akhtar, S., Rehman, S., & Jermy, B. R. (2026). Sustainable silver-integrated ZSM-5 coating on AISI 316 L implants: a multifunctional platform for controlled cisplatin delivery and antifungal activity. Journal of Saudi Chemical Society, 30(4), Article 55. https://doi.org/10.1007/s44442-026-00108-3

Image Credits: AI Generated

DOI: 10.1007/s44442-026-00108-3

Keywords: zeolite coating, ZSM-5, silver nanoparticles, AISI 316L stainless steel, cisplatin delivery, antifungal activity, Candida albicans, corrosion resistance, hydrothermal synthesis, metakaolin, drug release, biomaterials