A Study of Porous Poly(L-lactide) as a Scaffold for Osteogenesis Enhancement

Abstract

Our research group has developed a mechanism of inducing hierarchical porous structure along PLLA electrospun fibres. PLLA/HA/Keratin and PLLA/PCL complex membrane system and DOP/SiNP coated PLLA membrane were fabricated, and their osteogenesis in-vitro performances were monitored and compared with the pristine ones. The contact angle analysis states that the surface hydrophobicity of the porous samples was significantly higher than that of non-porous samples. Although the addition of HA and KE improved the water affinity, the resazurin and ALP assay suggested that the water-repelling surfaces of porous samples demonstrated lower cell attachment and proliferation rate in general. This is a result of a low cell-substrate contact points on the porous roughened surface, which consequently suggested that the porous PLLA sample is not preferable for cell culture, but more susceptible for advanced modifications for better in-vitro performance. SEM and live/dead assay were used for a better visual examination of such result. The subsequent experiment relied on DOP/SiNP coated PLLA membrane as a modification. The result showed that the topography of porous surface was negated by DOP network coverage and SiNP fulfilment. The hydrophobicity was reduced at moderate SiNP concentration (5%), and cell metabolism intensity was increased. However, higher concentration of SiNP resulted in cytotoxicity. Meanwhile, at highest concentration (30%) of PCL in PCL/PLLA blend, hydrophobicity was reduced, and cell metabolism was improved as well. Lowered hydrophobicity was caused by pore closure induced by PCL re-condensation. This thus gained extra cell attach rate for the sample. Both modifications, the introduction of DOP/SiNP coating and PCL blending system, received promising results in terms of increasing surface hydrophilicity of porous PLLA fibrous system thus enhanced the cell attachment rates.

Date of Award	1 Aug 2024
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Hugh Gong (Supervisor) & Jiashen Li (Supervisor)