Purpose: To control degradation and protein release using thermo-responsive hydrogels for localized delivery of anti-angiogenic proteins.
Methods: Thermo-responsive hydrogels derived from N-isopropylacrylamide (NIPAAm) and crosslinked with poly(ethylene glycol)-co-(L-lactic acid) diacrylate (Acry-PLLA-b-PEG-b-PLLA-Acry) were synthesized via free radical polymerization in the presence of glutathione, a chain transfer agent (CTA) added to modulate their degradation and release properties. Immunoglobulin G (IgG) and the recombinant proteins Avastin® and Lucentis® were encapsulated in these hydrogels and their release was studied.
Results: The encapsulation efficiency of IgG was high (75-87%) and decreased with CTA concentration. The transition temperature of these hydrogels was below physiological temperature, which is important for minimally invasive therapies involving these materials. The toxicity from unreacted monomers and free radical initiators was eliminated with a minimum of three buffer extractions. Addition of CTA accelerated degradation and resulted in complete protein release. Glutathione caused the degradation products to become solubilized even at 37°C. Hydrogels prepared without glutathione did not disintegrate nor released protein completely after 3 weeks at 37°C. PEGylation of IgG postponed the burst release effect. Avastin® and Lucentis® released from degraded hydrogels retained their biological activity.
Conclusions: These systems offer a promising platform for the localized delivery of proteins.
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http://dx.doi.org/10.1007/s11095-013-1195-0 | DOI Listing |
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January 2025
State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.
Gels
December 2024
"Petru Poni" Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley 41A, 700487 Iasi, Romania.
An imbalance in the body's pH or temperature may modify the immune response and result in ailments such as autoimmune disorders, infectious diseases, cancer, or diabetes. Dual pH- and thermo-responsive carriers are being evaluated as advanced drug delivery microdevices designed to release pharmaceuticals in response to external or internal stimuli. A novel drug delivery system formulated as hydrogel was developed by combining a pH-sensitive polymer (the "biosensor") with a thermosensitive polymer (the delivery component).
View Article and Find Full Text PDFMacromol Rapid Commun
December 2024
Eye Center, Affiliated Second Hospital, School of Medicine, Zhejiang University, Hangzhou, 310027, China.
Poly(N-isopropyl acrylamide) (PNIPAm)-based smart hydrogels are widely employed in emerging applications such as drug delivery and tissue engineering, because their lower critical solution temperature (LCST) is close to physiological conditions. However, the dense chain collapse during the thermo-responsive phase transition restricts water diffusion, resulting in limited volumetric change. Here, a pure PNIPAm hydrogel that achieves a large-scale volume transition by incorporating PNIPAm microgels, is presented.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
School of Civil Engineering and Transportation, Guangzhou University, Guangzhou 510006, China.
The development of a sustainable and eco-friendly silver-based hybrid nanocomposite for safe and efficient point-of-use (POU) water disinfection remains a challenge. Herein, a simple and facile approach was proposed for the in situ immobilization of silver nanoparticles (AgNPs) on chitosan-g-poly (sulfobetaine methacrylate) (CS-g-PSBMA) hydrogel beads, which have been achieved via graft copolymerization of sulfobetaine methacrylate along the chitosan chains followed by a drop method. The AgNPs-decorated CS-g-PSBMA hydrogel beads were characterized and their bactericidal efficacy towards Escherichia coli was evaluated concurrently with their anti-biofouling behaviors.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, University of Belgrade, Mike Petrovića Alasa 12-14, Vinča, 11351 Belgrade, Serbia.
Hydrogel nanocomposites that respond to external stimuli and possess switchable electrical properties are considered as emerging materials with potential uses in electrical, electrochemical, and biological devices. This work reports the synthesis and characterization of thermo-responsive and electroconductive hydrogel nanocomposites based on poly(-isopropylacrylamide) (PNiPAAm) and gold nanoparticles (nanospheres-AuNPs and nanorods-AuNRs) using two different synthetic techniques. Method I involved γ-irradiation-induced crosslinking of a polymer matrix (hydrogel), followed by radiolytic formation of gold nanoparticles, while Method II included the chemical synthesis of nanoparticles, followed by radiolytic formation of a polymer matrix around the gold nanoparticles.
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