Zinc oxide (ZnO) has been considered as one of the potential materials in solar cell applications, owing to its relatively high conductivity, electron mobility, stability against photo-corrosion and availability at low-cost.

Electroactive biomaterials are fascinating for tissue engineering applications because of their ability to deliver electrical stimulation directly to cells, tissue, and organs. One particularly attractive conductive filler for electroactive biomaterials is silver nanoparticles (AgNPs) because of their high conductivity, antibacterial activity, and ability to promote bone healing. However, production of AgNPs involves a toxic reducing agent which would inhibit biological scaffold performance. This work explores facile and green synthesis of AgNPs using extract of Cilembu sweet potato and studies the effect of baking and precursor concentrations (1, 10 and 100 mM) on AgNPs’ properties. Transmission electron microscope (TEM) results revealed that the smallest particle size of AgNPs (9.95 ± 3.69 nm) with nodular morphology was obtained by utilization of baked extract and ten mM AgNO3. Polycaprolactone (PCL)/AgNPs scaffolds exhibited several enhancements compared to PCL scaffolds. Compressive strength was six times greater (3.88 ± 0.42 MPa), more hydrophilic (contact angle of 76.8 ± 1.7°), conductive (2.3 ± 0.5 × 10−3 S/cm) and exhibited anti-bacterial properties against Staphylococcus aureus ATCC3658 (99.5% reduction of surviving bacteria). Despite the promising results, further investigation on biological assessment is required to obtain comprehensive study of this scaffold. This green synthesis approach together with the use of 3D printing opens a new route to manufacture AgNPs-based electroactive with improved anti-bacterial properties without utilization of any toxic organic solvents.

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Polyelectrolyte complexes (PECs) are attractive materials for drug delivery application as they offer simple preparations and high drug-loading efficiency. In this study, a novel method for preparing polyelectrolyte complex nanoparticles using a simple mixing method of chitosan and poly-2-acrylamido-2-methylpropane sulfonic acid (PAMPS) solutions is presented. The effect of chitosan concentrations was examined by fixing the PAMPS concentration at 0.01 %w/v, while chitosan concentrations were varied from 0.01 to 0.05 %w/v. Based on dynamic light scattering (DLS) and zeta sizer results, increasing the chitosan concentration led to increased average PEC particle sizes with broader particle distributions from 249.1 (polydispersity index/PDI 0.13) to 318.2 nm (PDI 0.19) and changed the particle surface charges from -5.85±0.34 to 11.95±0.84 mV. The addition of glutaraldehyde (GA) followed by dialysis eliminated sodium chloride (NaCl) and produced spherical PEC nanoparticles, confirmed via scanning electron microscopy (SEM) results. Among those samples, PECs with a chitosan concentration of 0.01 %w/v are the most promising drug carrier materials due to their negative surface charges, which promote prolonged circulation time in the bloodstream.