Efficient numerical methods for analyzing photonic crystals (PhCs) can be developed using the Dirichlet-to-Neumann (DtN) maps of the unit cells. The DtN map is an operator that takes the wave field on the boundary of a unit cell to its normal derivative. In frequency domain calculations for band structures and transmission spectra of finite PhCs, the DtN maps allow us to reduce the computation ...

In recent years, the development of smart drug delivery systems based on biodegradable polymeric nanoparticles has become of great interest. Drug-loaded nanoparticles can be introduced into the cell interior via endocytotic processes followed by the slow release of the drug due to degradation of the nanoparticle. In this work, poly(L-lactic acid) (PLLA) was chosen as the biodegradable polymer. ...

Poly lactic acid (PLLA) is a promising biopolymer, obtained from polymerization of lactic acid that is derived from renewable resources through fermentation. The characteristic brittleness of PLLA is attributed to slow crystallization rates, which results in the formation of the large spherulites. Its glass temperature is relative high, above room temperature and close to 60 °C, and therefore i...

Hydroxyapatite (Ca10(PO4)6(OH)2; HAp) has been currently used in hard tissue engineering due to its excellent biocompatibility and osteoconductivity [1-3]. However, the brittleness and relatively low mechanical properties of HAp limit its usefulness in bone implants. Thus, much attention has been focused on the hybridization of HAp with suitable polymers in order to obtain high mechanical prope...

A previously developed poly-L-lactide scaffold releasing granulocyte colony-stimulating factor (PLLA/GCSF) was tested in a rabbit chronic model of myocardial infarction (MI) as a ventricular patch. Control groups were constituted by healthy, chronic MI and nonfunctionalized PLLA scaffold. PLLA-based electrospun scaffold efficiently integrated into a chronic infarcted myocardium. Functionalizati...

Collagen and apatite were coprecipitated as a composite coating on poly L-lactic acid (PLLA) in an accelerated biomimetic process. The incubation solution contained collagen (1 g/L) and simulated body fluid with 5 times inorganic ionic concentrations as human blood plasma. The coating formed on PLLA films and scaffolds after a 24-h incubation was characterized by using energy-dispersive X-ray s...

Many sites are contaminated with petroleum hydrocarbons (PHCs). In some cases, these PHCs may be biorecalcitrant and therefore the soils contaminated with these PHCs are not amenable to remediation by biological treatment methods. Examples of sites containing biorecalcitrant PHCs are old flare pit sites. Flare pits are earthen pits that were once used for the storage and disposal of natural gas...

Split thickness skin graft (STSG) implantation is one of the standard therapies for full thickness wound repair when full thickness autologous skin grafts (FTG) or skin flap transplants are inapplicable. Combined transplantation of STSG with dermal substitute could enhance its therapeutic effects but the results remain unsatisfactory due to insufficient blood supply at early stages, which cause...

The Polyvinylpyrrolidone (PVP) / Poly (L-lactic acid) (PLLA) ultrafine blend fibers have been prepared for the first time by electrospinning. Trichloromethane was found to be the co-solvent for electrospinning. The PVP/PLLA blend solutions in various ratios were studied for electrospinning into ultrafine fibers. The morphology of the fibers was shown by scanning electron microscope (SEM). It wa...

Terminally differentiated somatic cells can rapidly change phenotypes when they are isolated from their native tissue and cultured in vitro. This problem may become a barrier to tissue engineering-based organ reconstruction, which utilizes somatic cells. The present study was designed to validate the feasibility of maintaining the urothelial cell phenotype in a tissue-specific ureteral scaffold...