γ-irradiated chitosan-polyvinyl pyrrolidone hydrogels as pH-sensitive protein delivery system

Influence of Poly (Ethylene Glycol) on the Characteristics of γ Radiation-Crosslinked Poly (Vinyl Pyrrolidone)-Low Molecular Weight Chitosan Network Hydrogels

“…Exposuring of PVPpolysaccharides blends to γ radiation would result in crosslinking of PVP chains, degradation of polysaccharides chains and grafting of polysaccharides on the PVP, simultaneously (Abad et al 2003). The irradiation of PVP-LMC blends yield to the formation of hydrogel consisting of semi interpenetrating polymer network (semi-IPN), where LMC chains entangled within the crosslinked PVP (Dergunov & Mun 2009). Hydrogel L has highest density of crosslinked network among series of hydrogel L (L10, L15, L20) due to the highest gel fraction indicated.…”

“…Chitosan also formulated into hydrogels for drug carrier application. This cationic polymer interacts with negatively charged drugs and protects the drugs from degradation by enzymes (Archana et al 2013;Dergunov & Mun 2009). Besides chitosan, degraded chitosan or low molecular weight chitosan (LMC) also demonstrates special property.…”

Long-term delivery of protein therapeutics

“…However, chemical cross-linking may lead to toxic side effects due to cross-linking agents or unwanted reactions with proteins drugs 71 . Sergey A et al utilized γ-irradiation to form cross-linked hydrogels consisting of chitosan (CS) and polyvinylpyrrolidone (PVP) for pH sensitive oral delivery of proteins 72 . The cross-linked hydrogels showed pH dependent swelling with marked swelling under acidic pH.…”

“…BSA loading in cross-linked gel was driven by charge-charge interactions between CS and BSA molecules. Hence, negligible amount of BSA was released (<10%) from CSPVP hydrogels at acidic pH (pH 1.5), compared to 40-90% released at pH 7.4 within 24 h [Figure 7] 72 . Similarly, in order to facilitate oral protein delivery and prevent protein degradation at acidic gastric pH, Zhang Y et al developed pH responsive gels using p(PEGMA-g-MAA) with triethylene glycol dimethacrylate as cross-linking agent 73 .…”

“…Key: CSPVP1: Cs:PVP 1:1 w/w crosslinked at 3.2 kGy, CSPVP2: Cs:PVP 1:1 w/w crosslinked at 5 kGy, CSPVP3: Cs:PVP 1:2 w/w crosslinked at 3.2 kGy and CSPVP4: Cs:PVP 1:2 w/w crosslinked at 5 kGy. Reproduced with permission from [72]. …”