Selective laser melting–enabled electrospinning: Introducing complexity within electrospun membranes

Additive manufacturing technologies enable the creation of very precise and well-defined structures that can mimic hierarchical features of natural tissues. In this article, we describe the development of a manufacturing technology platform to produce innovative biodegradable membranes that are enhanced with controlled microenvironments produced via a combination of selective laser melting techniques and conventional electrospinning. This work underpins the manufacture of a new generation of biomaterial devices that have significant potential for use as both basic research tools and components of therapeutic implants. The membranes were successfully manufactured and a total of three microenvironment designs (niches) were chosen for thorough characterisation. Scanning electron microscopy analysis demonstrated differences in fibre diameters within different areas of the niche structures as well as differences in fibre density. We also showed the potential of using the microfabricated membranes for supporting mesenchymal stromal cell culture and proliferation. We demonstrated that mesenchymal stromal cells grow and populate the membranes penetrating within the niche-like structures. These findings demonstrate the creation of a very versatile tool that can be used in a variety of tissue regeneration applications including bone healing

Fabrication of electrospun mucoadhesive membranes for therapeutic applications in oral medicine.

Oral mucosal lesions are related to several etiologies including trauma, infection, and immunologic and neoplastic diseases. Their prevalence varies greatly depending on ethnicity, gender and exposure to risk factors. Currently, most oral mucosal lesions are treated with creams, mouthwashes or gels containing suitable drugs. However, topical medications may be relatively ineffective as they are removed rapidly from oral surfaces, limiting drug contact times. Systemic medications might be more effective, but are associated with unacceptable off-target side effects. The aim of this study was to produce novel polymeric mucoadhesive membranes for therapeutic applications on the oral mucosa using electrospinning. Polyvinylpyrrolidone (PVP) and Eudragit RS100® (RS100) were used for the fabrication of membranes, whilst dextran (Dex) or poly(ethylene oxide) (PEO) particles were incorporated to enhance their mucoadhesive properties. An electrospun poly(caprolactone) (PCL) backing layer was added to create a dual-layer system. Solution properties were studied using rheometry, and membranes were characterized using differential thermal analysis and scanning electron microscopy. Solubility, surface hydrophobicity and adhesion properties were also investigated. Solution viscosity varied depending on composition and concentration, affecting fiber production. The addition of RS100 to PVP resulted in reduced membrane porosity and solubility, and increased surface hydrophobicity and in vitro adhesion times. Dex and PEO particles were located on the surface of the fibers. A PCL backing layer was successfully produced, with enhanced attachment between layers achieved through thermal treatment. PVP homopolymer membranes did not adhere to plastic or porcine mucosa, whereas PVP/RS100 membranes with and without PEO or Dex were tightly adherent. In conclusion, PVP and RS100 may be combined to tailor membrane properties. Furthermore, electrospinning facilitated the production of membranes consisting of mucoadhesive-fabricated fibers displaying increased surface area and long-lasting adhesive properties. These novel compositions exhibit great potential for the fabrication of mucoadhesive patches for therapeutic applications in oral medicine