Biology subjects

Alexander, C.

Publications and source records attributed to Alexander, C..

2 recordsLinked to original sources

bioRxiv2020

Designing Topographically Textured Microparticles For Induction and Modulation of Osteogenesis in Mesenchymal Stem Cell Engineering

Mesenchymal stem cells have been the focus of intense research in bone development and regeneration. We demonstrate the potential of microparticles as modulating moieties of osteogenic response by utilizing their architectural features. Topographically textured microparticles of varying microscale features were produced by exploiting phase-separation of a readily-soluble sacrificial component from polylactic acid. The influence of varying topographical features on primary human mesenchymal stem cell attachment, proliferation and markers of osteogenesis was investigated. In the absence of osteoinductive supplements, cells cultured on textured microparticles exhibited notably increased expression of osteogenic markers relative to conventional smooth microparticles. They also exhibited varying morphological, attachment and proliferation responses. Significantly altered gene expression and metabolic profiles were observed, with varying histological characteristics in vivo. This study highlights how tailoring topographical design offers cell-instructive 3D microenvironments which allow manipulation of stem cell fate by eliciting the desired downstream response without use of exogenous osteoinductive factors.

bioengineering↗

bioRxiv2019

Development of bioactive electrospun scaffolds suitable to support skin fibroblasts and release Lucilia sericata maggot excretion/secretion

Larval therapy has been reported to exert beneficial actions upon chronic wound healing by promoting granulation tissue formation, antimicrobial activity and degrading necrotic tissue. However, the use of live maggots is problematic for patient acceptance, and thus there is a need to develop materials which can adsorb and release therapeutic biomolecules from maggot secretions. Here we describe the fabrication of a novel bioactive scaffold that can be loaded with Lucilia sericata maggot excretion/secretion (L. sericata maggot E/S) for wound therapy, and which also provides structural stability for mammalian cell-growth and migration. We show that electrospun scaffolds can be prepared from polycaprolactone-poly (ethylene glycol)-block copolymer (PCL-b-PEG) blended with PCL, to form fibres with average diameters of ~4 m. We further demonstrate that the fibres are able to be loaded with L. sericata maggot E/S, in order to influence fibroblast migration through protease activity. Finally, we show that after 21 days, the cumulative amount of released L. sericata maggot E/S was ~14 g/mL from PCL-b-PEG/PCL scaffolds and that the protease activity of L. sericata maggot E/S was preserved when PCL-b-PEG/PCL scaffolds were used as the release platform.

bioengineering↗