University of Peradeniya

About: University of Peradeniya is a education organization based out in Kandy, Sri Lanka. It is known for research contribution in the topics: Population & Poison control. The organization has 5970 authors who have published 7388 publications receiving 197002 citations.

Synthesis of magnetite nanoparticles by top-down approach from a high purity ore

Abstract: This study attempts to synthesize magnetite nanoparticles from a high purity natural iron oxide ore found in Panvila, Sri Lanka, following a novel top-down approach. Powder X-Ray diffraction, elemental analysis, and chemical analysis data confirmed the ore to be exclusively magnetite with Fe2+: Fe3+ ratio of 1 : 2. Surface modified magnetite nanoparticles were synthesized by destructuring of this ore using a top-down approach in the presence of oleic acid. These oleic acid coated nanoparticles were further dispersed in ethanol resulting in stable nanomagnetite dispersion. Interestingly, the nanoparticles demonstrated a spherical morphology with a particle size ranging from 20 to 50 nm. Magnetic force microscopic data was used to confirm the topography of the nanoparticles and to study the magnetic domain structure.

Seed dormancy and storage behaviour in tropical Fabaceae: a study of 100 species from Sri Lanka

Abstract: Seeds of legumes are generally considered to have physical dormancy and to be orthodox, but most seed biologists are unaware of the various kinds and combinations of dormancy and storage behaviour in seeds of this family. The aim of our study was to document the dormancy and storage behaviour of seeds of 100 native and introduced tropical Fabaceae species in Sri Lanka and classify them into germination/storage behaviour categories. Moisture content (MC) was 29% for those of six. Seeds of these six species had low tolerance for desiccation and for low temperatures. Thus, seeds of six species are non-orthodox and 94 species orthodox. Nine of the 100 species were non-dormant, and 2, 3 and 86 had physiological, physiological epicotyl and physical dormancy, respectively. Six germination/storage behaviour categories were identified among the 100 species. However, as in extratropical regions of the world, orthodox storage behaviour and physical dormancy are characteristic of seeds of the majority of species of Fabaceae in tropical Sri Lanka.

Drug-Loaded Halloysite Nanotube-Reinforced Electrospun Alginate-Based Nanofibrous Scaffolds with Sustained Antimicrobial Protection

Abstract: Halloysite nanotube (HNT)-reinforced alginate-based nanofibrous scaffolds were successfully fabricated by electrospinning to mimic the natural extracellular matrix (ECM) structure which is beneficial for tissue regeneration. An antiseptic drug, cephalexin (CEF)-loaded HNT, was incorporated into the alginate-based matrix to obtain sustained antimicrobial protection and robust mechanical properties, the key criteria for tissue engineering applications. Electron microscopic imaging and drug release studies revealed that CEF had penetrated into the lumen space of the HNT and also deposited on the outer walls, with a total loading capacity of 30 wt %. Moreover, the diameter of alginate-based nanofibers of the scaffolds ranged from 40 to 522 nm with well-aligned HNTs, resulting in superior mechanical properties. For instance, the addition of 5% (w/w) HNT improved the tensile strength (σ) and elastic modulus by 3-fold and 2-fold, respectively, compared to those of the alginate-based scaffolds without HNT. The fabricated scaffolds exhibited remarkable antimicrobial properties against both Gram-negative and Gram-positive bacteria, and the cytotoxicity studies confirmed the nontoxicity of the fabricated scaffolds. Drug release kinetics showed that CEF inside HNTs diffuses within 24 h and that the diffusion of the drug is delayed by 7 days once the CEF-loaded HNTs are incorporated into the alginate-based nanofibers. These fabricated alginate-based electrospun scaffolds with enhanced mechanical properties and sustained antimicrobial protection hold great potential to be used as artificial ECM scaffolds for tissue engineering applications.