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Injectable Supramolecular Polymer-Nanoparticle Hydrogels for Cell and Drug Delivery Applications
Published on: February 7, 2021
Novel thymopentin release systems prepared from bioresorbable PLA-PEG-PLA hydrogels
Yan Zhang1, Xiaohan Wu, Yaru Han
1Department of Materials Science, Fudan University, Shanghai 200433, China.
International Journal of Pharmaceutics
|November 10, 2009
Summary
New stereocomplex PLA-PEG-PLA hydrogels show potential as drug carriers. These bioresorbable materials effectively deliver Thymopentin (TP5), demonstrating immunization efficacy in vivo.
Area of Science:
- Biomaterials Science
- Polymer Chemistry
- Drug Delivery Systems
Background:
- Stereocomplexation of poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) with poly(ethylene glycol) (PEG) forms bioresorbable hydrogels.
- These hydrogels exhibit viscoelastic properties suitable for drug encapsulation.
Purpose of the Study:
- To synthesize and characterize stereocomplex poly(lactide)-PEG-poly(lactide) (PLA-PEG-PLA) hydrogels.
- To evaluate the potential of these hydrogels as carriers for hydrophilic drugs, using Thymopentin (TP5) as a model.
- To investigate the in vivo efficacy of TP5-loaded hydrogels for immunization.
Main Methods:
- Ring-opening polymerization of lactide isomers with dihydroxyl PEG using zinc lactate catalyst.
- Hydrogel formation via stereocomplexation of PLLA-PEG-PLLA and PDLA-PEG-PDLA.
- Rheological measurements for viscoelasticity and degradation assessment.
- In vitro drug release studies under varying conditions (copolymer concentration, drug load, molar mass).
- In vivo studies assessing thymus morphology and immune response (CD4+/CD8+ ratio).
Main Results:
- Stereocomplex PLA-PEG-PLA hydrogels were successfully synthesized and characterized.
- Drug release profiles showed an initial burst followed by sustained release, influenced by copolymer concentration and molar mass.
- Higher copolymer concentrations and higher PEG molar masses resulted in slower TP5 release.
- Hydrogels composed of both PLLA/PEG and PDLA/PEG exhibited slower release than single copolymer solutions.
- In vivo studies confirmed the immunization efficacy of TP5-loaded hydrogels, particularly at 25% concentration.
Conclusions:
- Stereocomplex PLA-PEG-PLA hydrogels are promising bioresorbable carriers for hydrophilic drugs.
- Controlled release of TP5 was achieved, with parameters like concentration and molar mass influencing release kinetics.
- The hydrogels demonstrated significant immunization efficacy in vivo, highlighting their therapeutic potential.
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