Controlled delivery of platelet-derived growth factor-BB from injectable microsphere/hydrogel composites
Hua Wu1, Jiaoyan Liu2, Jingjing Wu2
1Department of Nuclear Medicine and Minnan PET Center, the First Affiliated Hospital of Xiamen University, Xiamen 316003, PR China.
Colloids and Surfaces. B, Biointerfaces
|September 14, 2016
Summary
Injectable hydrogels were created using chitosan, silk fibroin, and glycerophosphate, loaded with platelet-derived growth factor-BB (PDGF-BB) microspheres. These novel composites offer sustained drug release and enhanced degradation resistance, retaining PDGF-BB bioactivity.
Area of Science:
- Biomaterials Science
- Tissue Engineering
- Drug Delivery Systems
Background:
- Platelet-derived growth factor-BB (PDGF-BB) is crucial for tissue regeneration.
- Developing injectable hydrogels with controlled release is essential for effective therapeutic delivery.
- Chitosan and silk fibroin are biocompatible polymers with potential in biomedical applications.
Purpose of the Study:
- To develop injectable, mechanically robust hydrogel composites for sustained PDGF-BB delivery.
- To investigate the influence of silk fibroin content and PDGF-BB loading on composite properties and release kinetics.
- To evaluate the in vivo degradation and bioactivity retention of the developed hydrogels.
Main Methods:
- Incorporation of PDGF-BB loaded gelatin microspheres (approx. 2μm) into chitosan/silk fibroin/glycerophosphate solutions.
- Characterization of hydrogel formation, rheological properties (fluidity, shear-thinning), and mechanical strength (elastic modulus).
- Assessment of in vitro PDGF-BB release profiles, in vivo degradation, and bioactivity assays (DNA synthesis, cell migration).
Main Results:
- The composite solutions formed injectable hydrogels between 32-37°C at pH ~7, exhibiting good fluidity and shear-thinning behavior at room temperature.
- Composites demonstrated significantly enhanced mechanical strength (approx. 10-fold increase in elastic modulus) compared to chitosan/GP gels.
- Sustained, near-linear PDGF-BB release was achieved for up to 5 weeks, controllable by PDGF-BB load and silk fibroin content. Enhanced degradation resistance and retained bioactivity of released PDGF-BB were observed.
Conclusions:
- Developed injectable hydrogel composites show promise for sustained and controlled delivery of PDGF-BB.
- The tunable mechanical properties and degradation profile make these materials suitable for tissue engineering applications.
- The retained bioactivity of released PDGF-BB confirms the potential for promoting cellular functions crucial for tissue repair.
