Microstructure characterization through mechanical, electrokinetic and spectroscopic methods of polyampholyte gelatin hydrogels crosslinked with poly(vinyl alcohol)

Gelatin - glucosamine hydrochloride/crosslinked-Cyclodextrin Metal-organic frameworks @IBU composite hydrogel long-term sustained drug delivery system for osteoarthritis treatment

Osteoarthritis is a disease of articular cartilage degradation and inflammation of the joint capsule. Combining anti-inflammatory therapy with nutritional supplement is an effective means for the treatment of osteoarthritis. In this study, we prepared gelatin (Gel) - glucosamine hydrochloride (GH) mixed crosslinked-cyclodextrin metal-organic material (G-GH/CL-CD-MOF) composite hydrogel. Polyethylene glycol diglycidyl ether (PEGDE) was the crosslinking agent of GH and Gel to solve the problem of poor mechanical properties and water solubility at 37 ℃. CL-CD-MOF was fabricated through a simple one-step chemical reaction to crosslink the hydrophilic hydroxyl groups in CD-MOF with diphenyl carbonate (DPC). Electron microscopy and X-ray diffraction analysis of CL-CD-MOF showed perfect porous morphology with a chaotic internal structure. CL-CD-MOF@IBU was prepared by immersing CL-CD-MOF in high-concentration ibuprofen (IBU) solution. CL-CD-MOF@IBU was uniformly dispersed in Gel and GH mixed solution to prepare G-GH/CL-CD-MOF@IBU composite hydrogel long-term sustained drug delivery system. The compression curve of G-GH/CL-CD-MOF composite hydrogel showed a non-linear elastic behavior. The cyclic loading-unloading compression showed that the shape of the G-GH/CL-CD-MOF composite hydrogel can be kept intact under 50% strain. On the day 14, the G-GH/CL-CD-MOF@IBU composite hydrogel was degraded by 87.1%, 61% of IBU was released. G-GH/CL-CD-MOF@IBU exhibited good biocompatibility during co-culture with MC3T3-E1 cells. Briefly, the certain mechanical properties, sustained drug release behavior, and good biocompatibility of G-GH/CL-CD-MOF@IBU composite hydrogel showed that it has potential application in osteoarthritis treatment of long-term sustained nutritional supplement and anti-inflammatory synchronously.

Gelatin/carboxymethyl cellulose based stimuli-responsive hydrogels for controlled delivery of 5-fluorouracil, development, in vitro characterization, in vivo safety and bioavailability evaluation

Current work focuses on the synthesis and characterization of novel pH-sensitive biocompatible gelatin/carboxymethyl cellulose based hydrogels by free radical polymerization technique cross-linked with glutaraldehyde. Effect of pH, polymer ratio and variable crosslinking concentrations on dynamic swelling, equilibrium swelling, porosity, sol-gel analysis and in vitro release pattern was investigated. Hydrogel structure was confirmed by FTIR, XRD, and DSC. Moreover scanning electron microscopy confirmed the porous structure of gel network. Various structure property relationships like average molecular weight between crosslinks (Mc), solvent interaction parameters, volume fraction of polymer (V_2,s) and diffusion coefficient (D) that affect the release behaviour were determined. Results showed that maximum swelling and highest release of drug occurred at pH 1.2. Porosity and gel fraction increased by increasing polymer load. The invivo absorption and pharmacokinetics evaluation in rabbit's models revealed the controlled nature of hydrogels. MTT assay confirmed the biocompatible nature of blank hydrogels against Vero cell lines and cytotoxic potential against HeLa cell lines. The preliminary safety evaluation and oral tolerability revealed that the hydrogel solution is safe up to 4000 mg/kg body weight without causing any hematological or histopathological changes in rabbits.