Fabrication of interconnected microporous biomaterials with high hydroxyapatite nanoparticle loading.
Hydroxyapatite (HA) is known to promote osteogenicity and enhance the mechanical properties of biopolymers. However, incorporating a large amount of HA into a porous biopolymer still remains a challenge. In the present work, a new method was developed to produce interconnected microporous poly(glycolic-co-lactic acid) (PLGA) with high HA nanoparticle loading. First, a ternary blend comprising PLGA/PS (polystyrene)/HA (40/40/20 wt%) was prepared by melt blending under conditions for formation of a co-continuous phase structure. Next, a dynamic annealing stage under small-strain oscillation was applied to the blend to facilitate nanoparticle redistribution. Finally, the PS phase was sacrificially extracted, leaving a porous matrix. The results from different characterizations suggested that the applied small-strain oscillation substantially accelerated the migration of HA nanoparticles during annealing from the PS phase to the PLGA phase; nearly all HA particles were uniformly presented in the PLGA phase after a short period of annealing. After dissolution of the PS phase, a PLGA material with interconnected microporous structure was successfully produced, with a high HA loading above 30 wt%. The mechanisms beneath the experimental observations, particularly on the enhanced particle migration process, were discussed, and strategies for producing highly particle loaded biopolymers with interconnected microporous structures were proposed.
Zhang
Wei
W
School of Polymer Textile and Fiber Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
Yao
Donggang
D
Zhang
Qingwei
Q
Zhou
Jack G
JG
Lelkes
Peter I
PI
D001672:Biocompatible Materials / Q000737:chemistry*; D001704:Biopolymers / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011137:Polystyrenes / Q000737:chemistry; D016062:Porosity; D019736:Prostheses and Implants
D001672:Biocompatible Materials; D001704:Biopolymers; D011137:Polystyrenes; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D017886:Durapatite