Design Of Biomaterials Surface Features For Modulating Cellular Behaviors And Decellularized Extracellular Matrix

In basic cell biology and medical applications,in vitro cell culture represents a critical procedure.In general,a substrate is needed for cell culture.However,currently available materials are unable to meet the requirements of cells to achieve desirable outcomes.To develop new methodologies is the only way to achieve multifactorial control over the properties of bio materials for cell culture.In the present study,surface properties of substrate materials were modulated in terms of surface chemistry,mechanics and topographical features and cellular responses were investigated.First,polydimethylsiloxane(PDMS)was selected as the substratum and different surface modifications including serum incubation,collagen deposition and air plasma treatment were exploited in combination with variations in PDMS stiffness.Bovine articular chondrocytes(bAC)were cultured on these substrates.It was found that three modifications were all able to promote the adhesion and proliferation of bAC,with air plasma treatment the best.In addition,the stiffness of PDMS also affected the behaviors of bAC,but to a less extent compared to surface chemistry.Second,poly(s-caprolactone)(PCL)was processed into fibrous films with different fiber alignments via electro spinning and flat films through spin-coating.Rabbit bone marrow-derived mesenchymal stem cells(rMSC),human fibroblasts(HF)and bAC were cultured on these three PCL films.It was found that these films all well supported cell adhesion,proliferation,secretion of extracellular matrix(ECM),influence cell morphology and matrix structures,notably,cell alignment could be guided by aligned fibers.And gene expression were influenced by surface topoyraply with lower expression of Fibronectin and Collagen I levels in rMSC and HF on PCL electrospun fibers compared to flat films and vary gene expression of bAC on all PCL films.In the end,decellularization was carried out to generate 9 different in situ decellularized ECM(dECM)decorated PCL films(dECM/PCL).The components and structures were characterized in details and the behaviors of rMSC on these films were further evaluated.It was demonstrated that cell morphology and orientation as well as the matrix were dependent on the topographical features of the films(including flat films,random and aligned fibers).Although there was loss of ECM compositions during the decellularization process,the alignment of ECM components could be well maintained on aligned fibers after decellularization.The adhesion,proliferation and ECM production of rMSC on dECM/PCL films showed better performance than pristine PCL films.Moreover,dECM/PCL derived from different cell types had differential effects on rMSC.In conclusion,this study investigated the biological responses of cells on either PDMS or PCL with engineered surface properties and highlights the importance of biomaterials surface features in modulating the behaviors of cells,especially on dECM.This lays a solid foundation for designing bioactive substrates for cell culture.