Preparation and Characterization of Gelatin-Based PVA Film: Effect of Gamma Irradiation

Development of Mucoadhesive Vaginal Films for Metronidazole Delivery Using Methacryloylated, Crotonoylated, and Itaconoylated Gelatin Blends with Poly(vinyl alcohol)

PURPOSE

This work reports the development and characterisation of polymeric films composed of gelatin or its chemically modified derivatives (crotonoylated, itaconoylated, and methacryloylated gelatins) blended with polyvinyl alcohol (PVA). Metronidazole served as an antimicrobial drug in these formulations.

METHODS

The films were produced by casting aqueous solutions of polymers, followed by solvent evaporation. Their structure and physicochemical characteristics were studied using Fourier transform infrared spectroscopy, scanning electron microscopy, and mechanical testing. The thickness of the films, their folding endurance, the surface pH, and transparency were also evaluated. The mucoadhesive performance of the films was evaluated through an ex vivo detachment technique involving freshly excised sheep vaginal tissues. In vitro cumulative drug release studies were conducted using Franz diffusion cells.

RESULTS

The results demonstrate that incorporating unsaturated functional groups into gelatin improves its mucoadhesive properties compared to native gelatin. The drug release experiments conducted in vitro showed that the cumulative release from pure gelatin/PVA films was found to be 49 ± 2%, whereas modified gelatins/PVA (70:30) films released ~ 64-71%.

CONCLUSION

These findings suggest that modified gelatins could serve as effective excipients in designing mucoadhesive formulations for vaginal administration, with potential applications extending to other transmucosal drug delivery systems.

Design of Poly(lactic) acid/gelatin core-shell bicomponent systems as a potential wound dressing material

The electrospun core-shell nanofiber has great many advantages such as different types of solvents that can be used for changing flexibility, mechanical properties, or surface chemistry of fiber. Hydrophobic Poly(lactic) acid (PLA) and hydrophilic gelatin (Gel) were electrospun by various preparation conditions to design perfect bicomponent PLA:Gel nanofiber in a core-shell structure. Solvent types, the concentration of polymeric components, flow rate, and voltage of the electrospinning process were changed to optimization of nanofiber. According to the SEM images, the best nanofiber structure without beads was obtained at 0.4 ml/h flow rate of PLA solution and 1.2 ml/h flow rate of Gel solution at 45:55 (w:w %) weight ratio of PLA:Gel in trifluoroethanol solvent with a 10 kV voltage at 10 cm distance to the collector. From the TEM images, the existence of the core-shell structure had been proved which all prepared nanofibers with 2,2,2-Trifluoroethanol solvent. Furthermore, contact angle measurements showed a change in wettability when the Gel amount was increased. Therefore, the mildest synthesis conditions were determined for bicomponent PLA:Gel core-shell nanofibers as a potential wound dressing and dual drug carrier materials.

Desalination of brackish water by gelatin-coated magnetite nanoparticles as a novel draw solute in forward osmosis process

This paper presents the optimization of synthesis of gelatin-coated magnetite nanoparticles (MNPs) and their application as a draw solute in forward osmosis (FO) process. Persicaria bistorta root extract is used as the gelatin crosslinker, and its efficiency is compared with glutaraldehyde as a common crosslinker. Also, the impact of the concentration of gelatin and the draw solution on the osmotic pressure of the produced draw solution has been investigated using response surface methodology. Using Persicaria bistorta root extract as the crosslinker in the optimized conditions, the highest osmotic pressure (1.01 bar) was achieved in a concentration of 7.7%w/v and 14246 mg/l for gelatin and draw solution, respectively. Using glutaraldehyde under the same conditions resulted in osmotic pressure of 1.06 bar which is very close to the pressure found for Persicaria bistorta root extract (1.01 bar), confirming the benefit of the latter as a gelatin crosslinker. Further, using a solution with gelatin-coated MNPs as the draw solution, deionized water as the feed solution, and an osmotic pressure difference of 1.5 in the FO process generated an initial water flux of 1.54 LMH. By repeating the process in nine more cycles, the initial water flux was reduced to 0.365 LMH. These experiments confirm the as-prepared gelatin-MNPs as a promising draw solution in the FO process.

Synergistic effect of silane cross-linker (APTEOS) on PVA/gelatin blend films for packaging applications

The objective of this work is to fabricate hydrogel films which are biodegradable and also fit for packaging applications. The hydrogel films were prepared by the reaction of polyvinyl alcohol and gelatin with and without 3-aminopropyltriethoxysilane (APTEOS) cross-linker. The hydrogel films were then characterized by FTIR spectroscopy, degree of swelling, TGA, SEM analysis and mechanical testing. The FTIR spectra of the hydrogel films confirmed the presence of both polymers and hydrogen bonding between them. TGA analysis confirmed the increase in thermal stability with the increase of cross-linker amount. SEM analysis confirmed the increase in uniformity of structure with the increase of cross-linker amount. The increase in cross-linker amount resulted in decrease of degree of swelling and increase of tensile strength. The biodegradability of hydrogel films was evaluated by performing soil burial test and found to be decreased with the increase of cross-linker amount. In order to balance the tensile strength and biodegradability, the optimum amount of cross-linker was determined which resulted in the formation of the best performing film. Finally, our best performing film was compared with other hydrogel films reported in the literature. Hence, the hydrogel films cross-linked with APTEOS are biodegradable, having high tensile strength and suitable for packaging purpose.

Development and characterization of sublingual films for enhanced bioavailability of selegiline hydrochloride

Low oral bioavailability of selegiline hydrochloride (SH) is primarily due to extensive first-pass metabolism and hence the need for an alternative pathway of administration. Herein, we report the development of sublingual SH films. The films were formulated with varying polymer composition (F1-F6) and evaluated for physicochemical characteristics, in vitro drug release and ex vivo permeation studies. The film F2 demonstrated satisfactory weight (10.60 mg), folding endurance (>200), drug content (11.44 mg/cm²), disintegration time (68 s), mucoadhesive strength (47.7 N/cm²), and controlled release for 30 min. The permeation studies exhibited a higher ex vivo sublingual flux than that of the plain drug. This study concludes that the SH film can provide a potential opportunity for sublingual drug delivery.

Gelatin/poly(vinyl alcohol) based hydrogel film - A potential biomaterial for wound dressing: Experimental design and optimization followed by rotatable central composite design

The development of hydrogel films for biomedical applications is interesting due to their characteristics. Hydrogel films based on gelatin and poly(vinyl alcohol) (PVA) are developed and characterized using a rotatable central composite design. The optimized hydrogel film is obtained by the function desirability of the Statistica® software and is also characterized by swelling kinetics, oxygen permeability, adhesiveness, TGA, DSC, and XRD. The results of the experimental design show that gelatin and PVA concentrations have a significant influence on the response variables, and the exposure doses to UV light show no significant effect. The optimized hydrogel film is elastic, presents good mechanical resistance and swelling capacity in water and exudate solution, is permeable to oxygen, and is capable of adjusting itself and maintains contact close to the skin. In this way, considering all the properties evaluated, the optimized film has characteristics suitable for biomedical applications as wound dressings.

Hyperthermia-Induced Controlled Local Anesthesia Administration Using Gelatin-Coated Iron-Gold Alloy Nanoparticles

The lack of optimal methods employing nanoparticles to administer local anesthesia often results in posing severe risks such as non-biocompatibility, in vivo cytotoxicity, and drug overdose to patients. Here, we employed magnetic field-induced hyperthermia to achieve localized anesthesia. We synthesized iron-gold alloy nanoparticles (FeAu Nps), conjugated an anesthetic drug, Lidocaine, and coated the product with gelatin to increase the biocompatibility, resulting in a FeAu@Gelatin-Lidocaine nano-complex formation. The biocompatibility of this drug-nanoparticle conjugate was evaluated in vitro, and its ability to trigger local anesthesia was also evaluated in vivo. Upon exposure to high-frequency induction waves (HFIW), 7.2 ± 2.8 nm sized superparamagnetic nanoparticles generated heat, which dissociated the gelatin coating, thereby triggering Lidocaine release. MTT assay revealed that 82% of cells were viable at 5 mg/mL concentration of Lidocaine, indicating that no significant cytotoxicity was induced. In vivo experiments revealed that unless stimulated with HFIW, Lidocaine was not released from the FeAu@Gelatin-Lidocaine complex. In a proof-of-concept experiment, an intramuscular injection of FeAu@Gelatin-Lidocaine complex was administered to the rat posterior leg, which upon HFIW stimulation triggered an anesthetic effect to the injected muscle. Based on our findings, the FeAu@Gelatin-Lidocaine complex can deliver hyperthermia-induced controlled anesthetic drug release and serve as an ideal candidate for site-specific anesthesia administration.

Influence of the PLGA/gelatin ratio on the physical, chemical and biological properties of electrospun scaffolds for wound dressings

Chronic wounds are a global health problem, and their treatments are difficult and long lasting. The development of medical devices through tissue engineering has been conducted to heal this type of wound. In this study, it was demonstrated that the combination of natural and synthetic polymers, such as poly (D-L lactide-co-glycolide) (PLGA) and gelatin (Ge), were useful for constructing scaffolds for wound healing. The aim of this study was to evaluate the influence of different PLGA/gelatin ratios (9:1, 7:3 and 5:5 (v/v)) on the physical, chemical and biological properties of electrospun scaffolds for wound dressings. These PLGA/Ge scaffolds had randomly oriented fibers with smooth surfaces and exhibited distances between fibers of less than 10 μm. The 7:3 and 5:5 PLGA/Ge scaffolds showed higher swelling, hydrophilicity and degradation rates than pure PLGA and 9:1 (v/v) PLGA/Ge scaffolds. Young's moduli of the scaffolds were 72 ± 10, 48 ± 6, 58 ± 6 and 6 ± 1 MPa for the pure PLGA scaffold and the 9:1, 7:3 and 5:5 (v/v) PLGA/Ge scaffolds, respectively. Mesenchymal stem cells (MSCs) seeded on all the PLGA/Ge scaffolds were viable, and the cells were attached to the fibers at the different analyzed timepoints. The most significant proliferation rate was observed for cells on the 7:3 PLGA/Ge scaffolds. Biocompatibility analysis showed that all the scaffolds produced inflammation at the first week postimplantation; however, the 7:3 and 5:5 (v/v) PLGA/Ge scaffolds were degraded completely, and there was no inflammatory reaction observed at the fourth week after implantation. In contrast, the 9:1 PLGA/Ge scaffolds persisted in the tissue for more than four weeks; however, at the eighth week, no traces of the scaffolds were found. In conclusion, the scaffolds with the 7:3 PLGA/Ge ratio showed suitable physical, chemical and biological properties for applications in chronic wound treatments.