Nanofiber-permeated, hybrid polymer/ceramic scaffolds for guided cell behavior

Abstract

The current gold-standard therapeutic strategies for bone grafts in the patient population are to use either allograft or autograft bone. Although these approaches have a long track record of utilization, neither is without risk to the patient, and there remains a desire in the field to improve treatment options. While there have been treatments approved by the FDA for full length growth factors and calcium salt-laden collagen sponges, these are not available for the entire population of potential bone graft patients. One viable strategy to focus on these concerns is to design an implantable bone graft substitute that can address all the negative drawbacks of autograft bone, allograft bone, and full length proteins. The work provides a preliminary investigation of synthetic, nanofiber-permeated, composite polymer/ceramic scaffold for bone repair using thermally induced phase separation, PLLA microspheres, and hydroxyapatite. The scaffolds as described have fiber diameters that mimic natural collagen ECM networks in bone as determined by scanning electron microscopy and will serve as the basis for future studies in substrate-guided bone tissue regeneration.

Regenerative Engineering of the Rotator Cuff of the Shoulder

“…Nanofibrous scaffolds are other major textile-based structures that are being studied in recent years for rotator cuff regeneration. , As the collagen fibers are comprised of a nano-micro-structured hierarchical arrangement in the native rotator cuff ECM, nanofiber matrices afford the possibility of recapitulating the architecture of native ECM. ,− Nanofibers can be fabricated using variety of techniques, including: template synthesis, electrospinning, melt electrospinning, phase separation, and self-assembly . Among these techniques, versatility and low setup cost make electrospinning the most common technique for fabricating fibers with sub-micrometer diameters. , The nanofibers are typically obtained in the form of non-woven mats by applying high voltage to a polymeric solution exiting the needle. , As the solution droplets exit the needle, it undergoes elongation and whipping resulting in the drastic reduction of fiber diameters from several micrometers to sub-micrometers (typically less than 500 nm). − An added advantage with the use of electrospun nanofibers is their versatility in terms of anisotropic mechanical properties, fiber morphology, encapsulate and deliver bioactive molecules (antimicrobial agents, drugs, nanoparticles), all of these can be achieved by modulating the electrospinning setup or parameters. ,,− For tissue regeneration, the advantage of using nanofibers include the mimicry of the native ECM structure with high surface are to volume ratio, high porosity (%), higher cell attachment along the fiber direction and efficient nutrient transportation through the porous structures .…”