Fabrication of Stimuli-Responsive Quince/Mucin Co-Poly (Methacrylate) Hydrogel Matrices for the Controlled Delivery of Acyclovir Sodium: Design, Characterization and Toxicity Evaluation

Development and Optimization of Stimuli-Responsive Fenugreek/Carrageenan-Co-poly (Methacrylate) Hydrogel Matrices for Controlled Delivery of 5-Fluorouracil

This study developed novel, stimuli-responsive, biocompatible fenugreek/carrageenanco-poly(methacrylate) hydrogels via free radical polymerization for pH-regulated 5-FU delivery. The hydrogels were evaluated for drug loading (75.2-96.39%), swelling kinetics, sol-gel fraction, electrolyte responsiveness, porosity, and in vitro drug release. Analytical techniques (FTIR, SEM, PXRD, DSC/TGA) confirmed hydrogel formation, drug-excipient compatibility, and thermal stability. FTIR verified cross-linking and 5-FU incorporation, while DSC/TGA and PXRD indicated reduced drug crystallinity and transition to an amorphous form. SEM revealed rough surfaces with porous networks, supporting high drug loading. The hydrogels exhibited pH-responsive swelling, with higher swelling at pH 7.4 (following second-order kinetics) and minimal swelling at pH 1.2. They also responded to monovalent and divalent cations. In vitro release at pH 7.4 showed controlled 5-FU delivery (68.40-96.81%) over 36 h, following non-Fickian diffusion and Higuchi kinetics. Acute oral toxicity studies confirmed biocompatibility and safety. These findings demonstrate that fenugreek/carrageenan-co-poly(methacrylate) hydrogels are promising biocompatible carriers for targeted, controlled 5-FU delivery, offering a safer option for colorectal cancer treatment and other chemotherapy regimens.

Exploring the potential of a pH-sensitive hydrogel sponge: interpenetrating network of tragacanth and pectin for controlled delivery of levosulpiride

The development of drug delivery systems that allow precise control over drug release pattern has fetched significant attention in the pharmaceutical field. This research work investigates the potential of a pH-sensitive interpenetrating network (IPN) composed of tragacanth and pectin as a carrier for the controlled release of levosulpiride. To enhance the solubility of poorly soluble drug levosulpiride, inclusion complexes were formed with beta cyclodextrin (βCD). The IPN was prepared by cross-linking tragacanth with pectin by adopting a green chemistry approach. The resulting cross-linked polymeric network was subjected to repetitive freeze-drying cycles for preparation of spongy mass. The physicochemical properties of the resultant product were thoroughly characterized using a range of analytical techniques, including Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal analyses (DSC/TGA), and X-ray diffraction (XRD). The physical parameters like sol-gel fraction (%), drug loading (%), swelling behavior, electrolyte responsiveness, and in vitro drug release profile of the developed sponge were systematically evaluated under varying pH conditions. Results of FTIR demonstrated the formation of cross-linked network, ruling out drug-excipient interaction. SEM analysis unveiled porous and rough geometry. Thermal analyses proved the hydrogel network thermally stable whereas, PXRD demonstrated the overall amorphous nature of the hydrogel sponge. The outcomes of physical parameters demonstrated an incremental trend in gel fraction from 63 to 85% on raising the molar concentration of cross-linker from TP1 to TP3. However, increasing tragacanth content escalation in gel fraction from 75 to 79% was noticed. While gel fraction was augmented from 79 to 83% with increasing pectin contents. The maximum drug loading formulation TP3 was computed to be 89%. Hydrogel sponges also demonstrated electrolyte responsiveness. The release profile indicated a pH-responsive behavior, with sustained release up to 10 h observed in a buffer solution of pH 6.8 and 7.4. In an acidic medium, a minor amount of drug was released during 10 h dissolution. Drug release kinetics was observed to be in zero order. The findings of this study highlight the promising potential of the tragacanth/pectin hydrogel sponge as a pH-sensitive dais for the controlled delivery of levosulpiride, emphasizing its potential application in personalized drug therapy and the treatment of gastrointestinal disorders.

Evolved enzymes in the metabolism of biological poly-acids: Applications in otolaryngological biocatalysis

This study explores evolved Hyaluronidase, Lipase, and Elastase's identification, characterization, and therapeutic potential to enhance tissue regeneration and drug delivery systems in otolaryngology. Hyaluronidase variant H5 exhibited a turnover number (k_cat) of 1500 min-1, a 200 % increase over wild-type (500 min-1), demonstrating superior hyaluronic acid degradation. Similarly, lipase variant L2 reached 1200 min-1 (400 min-1 wild-type), and elastase variant E3 showed a turnover of 2200 min-1 (1000 min-1 wild-type). Kinetic analyses revealed improved Km and Vmax values across variants, with Hyaluronidase Variant H5 achieving Km = 1.5 μM and Vmax = 3000 μM/min. Molecular Dynamics (MD) simulations indicated structural stability (average RMSD ~1.5 Å for H5) and strong hydrogen bonding (180 bonds), enhancing catalytic efficiency. In vitro assays demonstrated a 40 % enhancement in tissue regeneration and increased epithelial cell proliferation (100 % for Hyaluronidase Variant H5 vs. 60 % wild-type). In vivo studies in rabbits revealed a 30 % reduction in recovery time post-sinus surgery and a 50 % reduction in scar tissue formation. These findings underscore the potential of evolved enzymes in advancing drug delivery (DD) and tissue repair (TR), with implications for broader applications in wound healing and inflammatory diseases.

Trilayered nanocellulose-based patches loaded with acyclovir and hyaluronic acid for the treatment of herpetic lesions

This study focuses on the preparation of layered bacterial nanocellulose (BNC) patches for drug delivery and wound healing in the context of herpes labialis. Nanostructured patches were prepared by selective aqueous diffusion of acyclovir (ACV, antiviral drug), hyaluronic acid (HA, skin healing promoter), and glycerol (GLY, plasticizer and humectant) in the BNC network, followed by assembly into trilayered patches with ACV on the central layer of the patch (ACVT) or divided between two layers (ACVH), to modulate drug release. Both patches showed good layers' adhesion and thermal stability (125 °C), UV barrier properties, good static (Young's modulus up to 0.9 GPa (dry) and 0.7 GPa (wet)) and dynamic mechanical performance, and adhesion strength (21 kPa) comparable to or higher than other materials and commercial adhesives for wound healing. In vitro drug dissolution showed faster ACV release from the ACVH patch (77 ± 5 %, 10 min) than from the ACVT one (50 ± 7 %), suggesting efficient drug delivery. ACVH closely resembled a commercial cream formulation in terms of release and permeation profiles. The patches were non-cytotoxic toward L929 fibroblasts, promoting cell adhesion and wound closure (in vitro). These results underscore the dual-action potential of the layered patches for managing herpetic lesions.

Hydrogel-based hybrid membrane enhances in vitro ophthalmic drug evaluation in the OphthalMimic device

Envisaging to improve the evaluation of ophthalmic drug products while minimizing the need for animal testing, our group developed the OphthalMimic device, a 3D-printed device that incorporates an artificial lacrimal flow, a cul-de-sac area, a moving eyelid, and a surface that interacts effectively with ophthalmic formulations, thereby providing a close representation of human ocular conditions. An important application of such a device would be its use as a platform for dissolution/release tests that closely mimic in vivo conditions. However, the surface that artificially simulates the cornea should have a higher resistance (10 min) than the previously described polymeric films (5 min). For this key assay upgrade, we describe the process of obtaining and thoroughly characterizing a hydrogel-based hybrid membrane to be used as a platform base to simulate the cornea artificially. Also, the OphthalMimic device suffered design improvements to fit the new membrane and incorporate the moving eyelid. The results confirmed the successful synthesis of the hydrogel components. The membrane's water content (86.25 ± 0.35 %) closely mirrored the human cornea (72 to 85 %). Furthermore, morphological analysis supported the membrane's comparability to the natural cornea. Finally, the performance of different formulations was analysed, demonstrating that the device could differentiate their drainage profile through the viscosity of PLX 14 (79 ± 5 %), PLX 16 (72 ± 4 %), and PLX 20 (57 ± 14 %), and mucoadhesion of PLXCS0.5 (69 ± 1 %), PLX16CS1.0 (65 ± 3 %), PLX16CS1.25 (67 ± 3 %), and the solution (97 ± 8 %). In conclusion, using the hydrogel-based hybrid membrane in the OphthalMimic device represents a significant advancement in the field of ophthalmic drug evaluation, providing a valuable platform for dissolution/release tests. Such a platform aligns with the ethical mandate to reduce animal testing and promises to accelerate the development of safer and more effective ophthalmic drugs.

A bioactive self-healing hydrogel wound-dressing based on Tragacanth gum: Structural and invitro biomedical investigations

The design and development of wound-dressing hydrogels with desirable therapeutic effects and proper mechanical and self-healing properties are crucial in the healthcare sector. This research aims to prepare a new self-healing hydrogel based on Tragacanth, polyvinyl alcohol, and borax to be used as a wound dressing, the hydrogel was first prepared through a simple and one-pot reaction. The efficiency of the resulting product was then assessed based on the rheological and self-healing tests as well as cellular tests on a mouse fibroblast cell line (L929) including toxicity and scratch tests as well as the investigation of the expression of TGFβ1, TGFβ2, and VEGF-A gens (using Real-time PCR). The synthesized hydrogel exhibited proper mechanical strength, high self-healing features, and no toxicity (cell viability >100 %). Rheological studies indicate that hydrogels with a higher borax content (PVA: B ratio of 5:1) exhibit a higher storage modulus across all frequencies. The presence of hydrogel improved the migration of the L929 cells and scratch healing. The hydrogel also caused a significant improvement in the expression of the growth factors of the genes (P < 0.001). Therefore, it can be concluded that the prepared wound dressing can actively contribute to wound healing, opening promising potentials in medical applications.

Mimosa/quince seed mucilage-co-poly (methacrylate) hydrogels for controlled delivery of capecitabine: Simulation studies, characterization and toxicological evaluation

This research focused on developing pH-regulated intelligent networks using quince and mimosa seed mucilage through aqueous polymerization to sustain Capecitabine release while overcoming issues like short half-life, high dosing frequency, and low bioavailability. The resulting MSM/QSM-co-poly(MAA) hydrogel was evaluated for several parameters, including complex structure formation, stability, pH sensitivity, morphology, and elemental composition. FTIR, DSC, and TGA analyses confirmed the formation of a stable, complex cross-linked network, demonstrating excellent stability at elevated temperatures. SEM analysis revealed the hydrogels' smooth, fine texture with porous surfaces. PXRD and EDX results indicated the amorphous dispersion of Capecitabine within the network. The QMM9 formulation achieved an optimal Capecitabine loading of 87.17 %. The gel content of the developed formulations ranged from 65.21 % to 90.23 %. All formulations exhibited excellent swelling behavior, with ratios between 65.91 % and 91.93 % at alkaline pH. In vitro dissolution studies indicated that up to 98 % of Capecitabine was released after 24 h at pH 7.4, demonstrating the potential for sustained release. Furthermore, toxicological evaluation in healthy rabbits confirmed the system's safety, non-toxicity, and biocompatibility.

pH-Sensitive Hydrogels Fabricated with Hyaluronic Acid as a Polymer for Site-Specific Delivery of Mesalamine

Hydrogels with the main objective of releasing mesalamine (5-aminosalicylic acid) in the colon in a modified manner were formulated in the present work using a free-radical polymerization approach. Different ratios of hyaluronic acid were cross-linked with methacrylic and acrylic acids using methylenebis(acrylamide). The development of a new polymeric network and the successful loading of drug were revealed by Fourier transform infrared spectroscopy. Thermogravimetric analysis demonstrated that the hydrogel was more thermally stable than the pure polymer and drug. Scanning electron microscopy (SEM) revealed a rough and hard surface which was relatively suitable for efficient loading of drug and significant penetration of dissolution medium inside the polymeric system. Studies on swelling and drug release were conducted at 37 °C in acidic and basic conditions (pH 1.2, 4.5, 6.8, and 7.4, respectively). Significant swelling and drug release occurred at pH 7.4. Swelling, drug loading, drug release, and gel fraction of the hydrogels increased with increasing hyaluronic acid, methacrylic acid, and acrylic acid concentrations, while the sol fraction decreased. Results obtained from the toxicity study proved the formulated system to be safe for biological systems. The pH-sensitive hydrogels have the potential to be beneficial for colon targeting due to their pH sensitivity and biodegradability. Inflammatory bowel disease may respond better to hydrogel treatment as compared to conventional dosage forms. Specific amount of drug is released from hydrogels at specific intervals to maintain its therapeutic concentration at the required level.

A tissue-adhesive F127 hydrogel delivers antioxidative copper-selenide nanoparticles for the treatment of dry eye disease

Dry eye disease (DED) is currently the most prevalent condition seen in ophthalmology outpatient clinics, representing a significant public health issue. The onset and progression of DED are closely associated with oxidative stress-induced inflammation and damage. To address this, an aldehyde-functionalized F127 (AF127) hydrogel eye drop delivering multifunctional antioxidant Cu2-xSe nanoparticles (Cu2-xSe NPs) was designed. The research findings revealed that the Cu2-xSe nanoparticles exhibit unexpected capabilities in acting as superoxide dismutase and glutathione peroxidase. Additionally, Cu2-xSe NPs possess remarkable efficacy in scavenging reactive oxygen species (ROS) and mitigating oxidative damage. Cu2-xSe NPs displayed promising therapeutic effects in a mouse model of dry eye. Detailed investigation revealed that the nanoparticles exert antioxidant, anti-apoptotic, and inflammation-mitigating effects by modulating the NRF2 and p38 MAPK signalling pathways. The AF127 hydrogel eye drops exhibit good adherence to the ocular surface through the formation of Schiff-base bonds. These findings suggest that incorporating antioxidant Cu2-xSe nanoparticles into a tissue-adhesive hydrogel could present a highly effective therapeutic strategy for treating dry eye disease and other disorders associated with reactive oxygen species. STATEMENT OF SIGNIFICANCE: A new formulation for therapeutic eye drops to be used in the treatment of dry eye disease (DED) was developed. The formulation combines copper-selenium nanoparticles (Cu2-xSe NPs) with aldehyde-functionalized Pluronic F127 (AF127). This is the first study to directly examine the effects of Cu2-xSe NPs in ophthalmology. The NPs exhibited antioxidant capabilities and enzyme-like properties. They effectively eliminated reactive oxygen species (ROS) and inhibited apoptosis through the NRF2 and p38 MAPK signalling pathways. Additionally, the AF127 hydrogel enhanced tissue adhesion by forming Schiff-base links. In mouse model of DED, the Cu2-xSe NPs@AF127 eye drops demonstrated remarkable efficacy in alleviating symptoms of DED. These findings indicate the potential of Cu2-xSe NPs as a readily available and user-friendly medication for the management of DED.

Quince seed mucilage/β-cyclodextrin/Mmt-Na+-co-poly (methacrylate) based pH-sensitive polymeric carriers for controlled delivery of Capecitabine

In current work, quince seed mucilage and β-Cyclodextrin based pH regulated hydrogels were developed using aqueous free radical polymerization to sustain Capecitabine release patterns and to overcome its drawbacks, such as high dose frequency, short half-life, and low bioavailability. Developed networks were subjected to thermal analysis, Fourier transforms infrared spectroscopy, powder x-ray diffraction, elemental analysis, scanning electron microscopy, equilibrium swelling, and in-vitro release investigations to assess the network system's stability, complexation, morphology, and pH responsiveness. Thermally stable pH-responsive cross-linked networks were formed. Nanocomposite hydrogels were prepared by incorporating Capecitabine-containing clay into the swollen hydrogels. All the formulations exhibited equilibrium swelling ranging from 67.98 % to 92.98 % at pH 7.4. Optimum Capecitabine loading (88.17 %) was noted in the case of hydrogels, while it was 74.27 % in nanocomposite hydrogels. Excellent gel content (65.88 %-93.56 %) was noticed among developed formulations. Elemental analysis ensured the successful incorporation of Capecitabine. Nanocomposite hydrogels released 80.02 % longer than hydrogels after 30 h. NC hydrogels had higher t1/2 (10.57 h), AUC (121.52 μg.h/ml), and MRT (18.95 h) than hydrogels in oral pharmacokinetics. These findings imply that the pH-responsive carrier system may improve Capecitabine efficacy and reduce dosing frequency in cancer therapy. Toxicity profiling proved the system's safety, non-toxicity, and biocompatibility.

Development of Tofacitinib Loaded pH-Responsive Chitosan/Mucin Based Hydrogel Microparticles: In-Vitro Characterization and Toxicological Screening

Tofacitinib is an antirheumatic drug characterized by a short half-life and poor permeability, which necessitates the development of sustained release formulation with enhanced permeability potential. To achieve this goal, the free radical polymerization technique was employed to develop mucin/chitosan copolymer methacrylic acid (MU-CHI-Co-Poly (MAA))-based hydrogel microparticles. The developed hydrogel microparticles were characterized for EDX, FTIR, DSC, TGA, X-ray diffraction, SEM, drug loading; equilibrium swelling (%), in vitro drug release, sol–gel (%) studies, size and zeta potential, permeation, anti-arthritic activities, and acute oral toxicity studies. FTIR studies revealed the incorporation of the ingredients into the polymeric network, while EDX studies depicted the successful loading of tofacitinib into the network. The thermal analysis confirmed the heat stability of the system. SEM analysis displayed the porous structure of the hydrogels. Gel fraction showed an increasing tendency (74–98%) upon increasing the concentrations of the formulation ingredients. Formulations coated with Eudragit (2% w/w) and sodium lauryl sulfate (1% w/v) showed increased permeability. The formulations equilibrium swelling (%) increased (78–93%) at pH 7.4. Maximum drug loading and release (%) of (55.62–80.52%) and (78.02–90.56%), respectively, were noticed at pH 7.4, where the developed microparticles followed zero-order kinetics with case II transport. Anti-inflammatory studies revealed a significant dose-dependent decrease in paw edema in the rats. Oral toxicity studies confirmed the biocompatibility and non-toxicity of the formulated network. Thus, the developed pH-responsive hydrogel microparticles seem to have the potential to enhance permeability and control the delivery of tofacitinib for the management of rheumatoid arthritis.