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Hydrophilic silicate platelets, prepared from the two-step process of exfoliation and extractive isolation of layered silicate clays, were allowed to react with an alkyl anhydride and convert into organic-platelet hybrids of hydrophobic property. The exfoliative process was developed previously to isolate the silicate platelets of different sizes, including the platelets from the naturally occurring montmorillonite and synthetic fluorinated mica. The introduction of the hydrophobic organics through ionic exchanging with the sodium ions on the platelet surface (≡SiO -Na + ) was critical for rendering the silicate platelet in powder form and compatible with epoxy resin in curing into nanocomposites. The ultimate fine-dispersion of the hydrophobic platelets in epoxy matrices was observed by using transmission electron microscopy (TEM) and rendered the epoxies advanced high transparency, hardness, and particularly low coefficient of thermal expansion (CTE). The sustainable physical performance is suitable for the specific electronic applications such as encapsulation for light-emitting-diode devices.

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A novel approach of making a biomimetic nerve conduit was established by seeding adipose-derived adult stem cells (ADSCs) on the external wall of porous poly(d,l-lactic acid) (PLA) nerve conduits. The PLA conduits were fabricated using gas foaming salt and solvent-nonsolvent phase conversion. We examined the effect of two different porous structures (GS and GL) on ADSC growth and proliferation. The GS conduits had better structural stability, permeability, and porosity, as well as better cell viability at 4, 7, and 10 days. The epineuriallike tissue was grown from ADSC-seeded conduits cultured for 7 days in vitro and then implanted into 10-mm rat sciatic nerve defects for evaluation. The regeneration capacity and functional recovery were evaluated by histological staining, electrophysiology, walking track, and functional gait analysis after 6 weeks of implantation. Experimental data indicated that the autograft and ADSC-seeded GS conduits had better functional recovery than the blank conduits and ADSC-seeded GL conduits. The area of regenerated nerve and number of myelinated axons quantified based on the histology also indicated that the autograft and AGS groups performed better than the other two groups. We suggested that ADSCs may interact with endogenous Schwann cells and release neurotrophic factors to promote peripheral nerve regeneration. The design of the conduit may be critical for producing a biohybrid nerve conduit and to provide an epineurial-like support.

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