Matrix hydrophobicity hinders cell attachment in tissue engineered scaffolds. We proposed a facile seeding method to optimize cell presentation in nanofibrous mats formulated in a mixture of hydrophobic polycaprolactone (PCL), hydroxyapatite (HAp) mimicking bone surface roughness, and a ligand-supporting biopolymer. High-density osteoblast suspensions in serum-deficient media were seeded into composites arranged on a glass carrier sandwiched between cylindrical supports (seeding constructs) for 4 hours initial seeding and subsequently statically cultured in a complete medium for 7 days. Cell behavior and growth were analyzed by viability assays, LIVE/DEAD fluorescence labeled imaging, and electron microscopy. The zeta potential and contact angle of PCL-HAp nanofibers were altered by the addition of biopolymers, which directed cell attachment and proliferation. Modified seeding proved the benefit of collagen reinforcement to mediate cell-matrix interactions, which was demonstrated by enhancing cell spread with nearly twofold substantial growth during culture. The addition of gelatin showed a lower level of increased cell adhesion than collagen. Interestingly, clusters of spheroid cells were found in the chitosan composite with high cell adhesion on the first day, but the cells did not grow further until the end of the culture. In contrast, poor cell adhesion and inconsistent growth were found after conventional seeding and thus emphasized the potential role of modified seeding in supporting matrix performance as a cell carrier.

Background and Aim An antimicrobial delivery in the form of surface-modified lectin of lipid nanoparticles was proposed to improve cellular accumulation. ArtinM, an active toll-like receptor 2 (TLR2) agonist lectin isolated from cempedak ( Arthocarpus integrifolia) seeds, was selected to induce cellular engulfment of nanoparticles within infected host cells. Materials and Methods Lipid nanoparticles were prepared using the emulsification technique before electrostatic adsorption of artinM. The formula comprising of rifampicin, soy phospholipid, and polysorbate 80 was optimized by Box-Behnken design to produce the desired particle size, entrapment efficiency, and drug loading. The optimum formula was characterized for morphology, in vitro release, and cellular transport. Results and Discussion Soy phospholipid showed a profound effect on controlling drug loading and entrapment efficiency. Owing to its surface activity, polysorbate 80 contributed significantly to reduce particle size; however, a higher ratio to lipid concentration resulted in a decrease of rifampicin encapsulation. The adsorption of artinM on the surface of nanoparticles was accomplished by electrostatic binding at pH 4, where this process maintained the stability of encapsulated rifampicin. A high proportion of artinM adsorbed on the surface of the nanoparticles shown by haemagglutination assay, zeta potential measurement, and transmission electron microscopy imaging. Cellular uptake revealed by confocal microscopy showed the success in transporting Nile-red labelled nanoparticles across fibroblast cells. Conclusion The delivery system of nanoparticles bearing artinM becomes a potential platform technology for antibiotic targeting in the treatment of life-threatening chronic diseases caused by intracellular infections.