Untitled

Li, Zhenhua; Ning, Wen; Wang, Jumei; Choi, Augustine M.K.; Lee, Pui Yan; Tyagi, Pradeep; Huang, Leaf

doi:10.1023/a:1023887203111

Cited by 129 publications

(13 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is likely that the use of PEG-PLGA-PEG hydrogel to deliver simvastatin minimized the likelihood of exposing cells to a transiently high concentration of the drug at the time of injection. This tri-block polymer has been used extensively as a carrier for controlled drug or gene delivery [24,36,37]. Our pilot data in a separate study also demonstrated that the release profile of simvastatin from the PEG-PLGA-PEG gel in vitro was steady and sustainable (data not shown).…”

Section: Discussionmentioning

confidence: 56%

Intradiscal injection of simvastatin retards progression of intervertebral disc degeneration induced by stab injury

et al. 2009

View full text Add to dashboard Cite

IntroductionEarlier work indicates that the cholesterol-lowering drug, simvastatin, is anabolic to chondrogenic expression of rat intervertebral disc (IVD) cells, which suggests a potential role for simvastatin in IVD regeneration. In this study, we expand on our earlier work to test the effectiveness of simvastatin on disc degeneration utilizing a rat tail disc degeneration model.Methods30 rats that underwent 21 G needle-puncture at rat tail discs were injected with simvastatin-loaded poly(ethylene glycol)-poly(lactic acid-co-glycolic acid)-poly(ethylene glycol) (PEG-PLGA-PEG) gel (5 mg/ml) or vehicle control at 4 weeks after needle injury. All animals were sacrificed 2 weeks after simvastatin injection. Bone morphogenetic protein-2 (BMP-2), aggrecan, collagen type II, and collagen type I messenger ribonucleic acid (mRNA) expression in the rat nucleus pulposus (NP) were measured by real-time polymerase chain reaction (PCR). In vivo magnetic resonance imaging (MRI) was performed to monitor changes in disc degeneration. Rat discs were also assessed by histology using hematoxylin and eosin (H&E) and safranin O staining. In addition, the NP weight, glycosaminoglycan (sGAG) and DNA content were also measured.ResultsA single dose of simvastatin loaded in thermo-sensitive PEG-PLGA-PEG gel injected into the NP had the trend to increase aggrecan expression and sGAG content, and significantly increased mRNA levels of BMP-2, collagen type II, and the differentiation index (the ratio of collagen type II to collagen type I). The decreased NP weight, T2 intensity, as well as MRI index in the rat tail discs induced by needle puncture were significantly reversed after 2 weeks of simvastatin treatment. In addition, simvastatin treatment also improved histological changes induced by needle puncture.ConclusionsA single injection of simvastatin loaded in PEG-PLGA-PEG gel into rat tail discs had the potential to retard or regenerate the degenerative disc.

show abstract

Section: Discussionmentioning

confidence: 56%

Intradiscal injection of simvastatin retards progression of intervertebral disc degeneration induced by stab injury

et al. 2009

View full text Add to dashboard Cite

show abstract

“…First, the diblock copolymers of monomethoxy PEG-PLGA (MPEG-PLGA) were synthesized via ROP of D,L-lactide (DLLA) and glycolide (GA) on MPEG in the presence of Sn(oct) 2 as a catalyst, and subsequently, the triblock PEG-PLGA-PEG copolymers were prepared by coupling the diblock MPEG-PLGA copolymers to each other using an HDI coupling agent. The copolymer solutions existed at low temperatures, but became gels at 37 °C (sol-to-gel transition) [56–58], which were suitable for encapsulation and delivery of labile proteins [59,60]. An in vitro degradation test showed that these hydrogels maintained their integrity for more than 1 month.…”

Section: Hydrogel Design For Delivery Of Bioactive Factorsmentioning

confidence: 99%

Bioactive factor delivery strategies from engineered polymer hydrogels for therapeutic medicine

Nguyen

Alsberg

2014

Progress in Polymer Science

193

136

View full text Add to dashboard Cite

Polymer hydrogels have been widely explored as therapeutic delivery matrices because of their ability to present sustained, localized and controlled release of bioactive factors. Bioactive factor delivery from injectable biopolymer hydrogels provides a versatile approach to treat a wide variety of diseases, to direct cell function and to enhance tissue regeneration. The innovative development and modification of both natural-(e.g., alginate (ALG), chitosan, hyaluronic acid (HA), gelatin, heparin (HEP), etc.) and synthetic-(e.g., polyesters, polyethyleneimine (PEI), etc.) based polymers has resulted in a variety of approaches to design drug delivery hydrogel systems from which loaded therapeutics are released. This review presents the state-of-the-art in a wide range of hydrogels that are formed though self-assembly of polymers and peptides, chemical crosslinking, ionic crosslinking and biomolecule recognition. Hydrogel design for bioactive factor delivery is the focus of the first section. The second section then thoroughly discusses release strategies of payloads from hydrogels for therapeutic medicine, such as physical incorporation, covalent tethering, affinity interactions, on demand release and/or use of hybrid polymer scaffolds, with an emphasis on the last 5 years.

show abstract

“…Hydrogels, which can swell and do not dissolve in water, are cross-linked polymer networks containing a large amount of water [1,2]. They are widely studied and have been applied in many fields, such as drug delivery [2,3], gene delivery [4] and tissue engineering scaffolds [5,6] due to their excellent properties, such as intelligent responsiveness, biocompatibility. However, the traditional synthetic hydrogels have generally weak mechanical strength, poor toughness and low recoverability [7].…”

Section: Introductionmentioning

confidence: 99%

Biodegradable Poly(acrylic acid-co-acrylamide)/Poly(vinyl alcohol) Double Network Hydrogels with Tunable Mechanics and High Self-healing Performance

Jing

Liang

et al. 2019

Polymers

View full text Add to dashboard Cite

We proposed a novel strategy in the fabrication of biodegradable poly(acrylic acid-co-acrylamide)/poly(vinyl alcohol) (P(AAc-co-Am)/PVA) double network (DN) hydrogels with good mechanical and self-healing properties. In the DN hydrogel system, P(AAc-co-Am) polymers form a network through the ionic coordinates between –COO– and Fe3+ and hydrogen bonding between –COOH and –CONH2, while another network is fabricated by the complexation between PVA and borax. The influences of the composition on the rheological behaviors and mechanical properties of the synthesized DN hydrogels were investigated. The rheological measurements revealed that the viscoelasticity and stiffness of the P(AAc-co-Am)/PVA DN hydrogels increase as the acrylamide and Fe3+ concentrations increase. At 0.05 mmol of Fe3+ and 50% of acrylamide, tensile strength and elongation at break of P(AAc-co-Am)/PVA DN hydrogels could reach 329.5 KPa and 12.9 mm/mm, respectively. These properties arise from the dynamic reversible bonds existed in the P(AAc-co-Am)/PVA DN hydrogels. These reversible bonds also give good self-healing properties, and the maximum self-healing efficiency of P(AAc-co-Am)/PVA DN hydrogels is up to 96.4%. The degradation test of synthesized DN hydrogels was also conducted under simulated physiological conditions and the weight loss could reach 74% in the simulated intestinal fluid. According to the results presented here, the synthesized P(AAc-co-Am)/PVA DN hydrogels have a potential application prospect in various biomedical fields.

show abstract

Untitled

Abstract: These results suggest hydrogel formed by PEG-PLGA-PEG could be a promising platform for delivery of pDNA, which represents a novel strategy that may serve as a non-viral vector for gene therapy in wound healing.

Cited by 129 publications

References 12 publications

Intradiscal injection of simvastatin retards progression of intervertebral disc degeneration induced by stab injury

Intradiscal injection of simvastatin retards progression of intervertebral disc degeneration induced by stab injury

Bioactive factor delivery strategies from engineered polymer hydrogels for therapeutic medicine

Biodegradable Poly(acrylic acid-co-acrylamide)/Poly(vinyl alcohol) Double Network Hydrogels with Tunable Mechanics and High Self-healing Performance

Contact Info

Product

Resources

About