Homogeneous chitosan/poly(L-lactide) composite scaffolds prepared by emulsion freeze-drying.
The combination between chitosan (CS)-based hydrophilic extracellular matrix polysaccharide and polylactide (PLA)-based hydrophobic biodegradable aliphatic polyester is a challenge in the biomaterials field. This study investigated the formation of homogeneous chitosan/poly(L-lactide)  (CS/PLLA) porous composite scaffold using a novel emulsion freeze-drying technique. An oil-in-water (O/W) emulsification system was used in the presence of surfactant Tween-80, in which CS solution was used as the water phase and PLLA solution was used as the oil phase. The composite scaffolds  showed well interconnected pore structures and homogenous distribution of CS and PLLA when the PLLA volume fraction was not higher than 50%. Once the PLLA content increased to 75%, SEM micrographs demonstrated that the two components present phase separation region. FT-IR analysis revealed  that there are strong hydrogen bond interactions between CS and PLLA components. The porosity of the CS/PLLA composites was in the range of 85-90% and showed a slight decrease with increasing PLLA dose. The mechanical properties of the composites lay between that of the pure CS and the  PLLA scaffold. The compressive strength increased from 0.17 to 0.21 MPa, while the compressive modulus increased from 2.37 to 3.38 MPa as the PLLA contents increased from 25 to 75%. In vitro cytotoxicity was evaluated by MTT assay. The results indicated that MC3T3-E1 cell viability  and proliferation in the CS/PLLA scaffold were comparable to that in the CS scaffold, and much higher than that in the PLLA scaffold. The successful hydrophilic polysaccharide and hydrophobic polyester system offers a new delivery method of growth factors and a novel scaffold design for tissue  engineering.
Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, P. R. China.
Xufeng
X
Niu
Xiaoming
X
Li
Haifeng
H
Liu
Gang
G
Zhou
Qingling
Q
Feng
Fuzhai
F
Cui
Yubo
Y
Fan
D016475:3T3 Cells; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000633:toxicity; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry*; D004655:Emulsions; D005612:Freeze Drying / Q000379:methods*; D055595:Mechanical Phenomena; D051379:Mice; D055616:Microtechnology / Q000379:methods*; D011091:Polyesters / Q000737:chemistry*; D011136:Polysorbates / Q000737:chemistry; D016062:Porosity; D013501:Surface-Active Agents / Q000737:chemistry
D001672:Biocompatible Materials; D004655:Emulsions; D011091:Polyesters; D011136:Polysorbates; D013501:Surface-Active Agents; C033616:poly(lactide); D048271:Chitosan