Fabricating a robust POSS-PCL nanofiber scaffold for nesting of mesenchymal stem cells: potential application in bone tissue regeneration

BACKGROUND

According to recent studies, electrospun Poly (Ɛ-caprolactone) (PCL) is an absorbing candidate for the formulation of biocompatible scaffolds used in tissue engineering. Tissue engineering is a set of techniques for producing or reconstructing tissue, whose primary purpose is to restore or improve the function of tissues in the human body. Tissue engineering combines the principles of materials and cell transplantation to develop alternative tissues or promote endogenous regeneration. However, this electrospun scaffold, consisting of PCL, has disadvantages such as low cell adhesion, inactivity of the surface, osteoinduction, and acidic destruction of the scaffold that causes inflammation at the implant site, often making it unsuitable implant. This study aimed to improve PCL base cellular scaffolds with the formulation of polyhedral oligomeric silsesquioxane - Polycaprolactone (POSS-PCL) nanofiber scaffolds. The present research focuses on the synthesis of nanofibers for their cell interaction features, and application in bone tissue engineering and regeneration.

RESULTS

POSS/ PCL Nanocomposites with 2, 5, and 10 wt.% of POSS were synthesized in the Trichloromethane, then POSS - PCL Nanofibers were prepared by the electrospinning technique. In this study, the structures of nanohybrids and nanofibers have been evaluated by FTIR, HNMR, XRD, SEM, EDX, and DSC. The biocompatibility of formulated POSS-PCL scaffolds was detected using mesenchymal stem cells (MSCs). Then several parameters were examined, involving DCFH ROS detection system, gene expression (cell viability/apoptosis, osteogenesis potentiality, and redox molecular homeostasis.

CONCLUSIONS

Based on our results, POSS-PCL nano-scaffolds in comparison with PCL have shown a robust potentiality in homing, growth, and differentiation of stem cells. Synthesis of POSS-PCL Nanofibers and their potential application in Bone Regeneration.

A polyhedral oligomeric silsesquioxane-based bilayered dermal scaffold seeded with adipose tissue-derived stem cells: in vitro assessment of biomechanical properties

BACKGROUND

Although commercial skin substitutes are widely available, its use remains challenging at surgery and postoperatively. The high cost is also prohibitive. We designed and characterized a scaffold for dermal replacement, using advanced nanocomposite materials, which are known to have unique nanoscale features that enhance cellular behavior.

METHODS

A bilayered scaffold was developed using the nanocomposite, polyhedral oligomeric silsesquioxane, incorporated into poly(caprolactone-urea)urethane, resulting in a mechanically robust bioabsorbable polymer; forming the inner layer, which was designed with a range of porosities. The removable outer layer contained nanosilver. Tensile testing, surface tension, permeability, and scanning electron microscopy were performed. Optimal pore morphology for cellular proliferation was elucidated through adipose tissue-derived stem cell culture and a cell viability assay. All tests were repeated on Integra Dermal Regeneration Template.

RESULTS

The physical construct was easy to handle and clinically applicable. Macroporosity and permeability of scaffolds was demonstrated, confirmed by scanning electron microscopy. Both tensile strength and surface tension were comparable with skin; outer layer demonstrated hydrophobicity and inner layer showed hydrophilicity. Cell assay confirmed cellular proliferation onto the scaffold, comparable with Integra.

CONCLUSIONS

We demonstrate that a porous bilayered dermal scaffold could form the basis of a new generation of skin substitute that is both mechanically robust and harbors the ability for enhancing cell regeneration.