Electrospinning is useful for fabricating nanofibrous structure with different composition and morphologies. It offers great advantages through its geometrical structure and biomimetic property, which can provide a suitable environmental site for cell growth. The fiber diameter is entangled by the concentration of PCL with some adjustment of parameters during electrospinning process. PCL with lower concentration had bead structure while higher concentration had smooth fiber. The incorporation of nanoparticle hydroxyapatite (nHA) into poly(ɛ-caprolactone) fiber was studied. The fiber diameter of PCL was increased with the addition of nHA. Composition of fiber at lower concentrations of PCL and nHA into the polymer produced fiber with a homogenous distribution of nHA in PCL fiber with less agglomeration. The immersion of PCL/nHA fiber in simulated body fluid (SBF) had bone-like apatite layer on its surface while PCL showed no results. PCL/nHA showed high water uptake and had improved wettability compared to PCL alone, suggesting that PCL/nHA fibers were more hydrophilic than PCL fiber.

Tissue engineering fibrous scaffolds serve as three-dimensional (3D) environmental framework by mimicking the extracellular matrix (ECM) for cells to grow. Biodegradable polycaprolactone (PCL) microfibers were fabricated to mimic the ECM as a scaffold with 7.5% (w/v) and 12.5% (w/v) concentrations. Lower PCL concentration of 7.5% (w/v) resulted in microfibers with bead defects. The average diameter of fibers increased at higher voltage and the distance of tip to collector. Further investigation was performed by the incorporation of nanosized hydroxyapatite (nHA) into microfibers. The incorporation of 10% (w/w) nHA with 7.5% (w/v) PCL solution produced submicron sized beadless fibers. The microfibrous scaffolds were evaluated using various techniques. Biodegradable PCL and nHA/PCL could be promising for tissue engineering scaffold application.

Considering the important factor of bioactive nanohydoxyapatite (nHA) to enhance osteoconductivity or bone-bonding capacity, nHA was incorporated into an electrospun polycaprolactone (PCL) membrane using electrospinning techniques. The viscosity of the PCL and nHA/PCL with different concentrations of nHA was measured and the morphology of the electrospun membranes was compared using a field emission scanning electron microscopy. The water contact angle of the nanofiber determined the wettability of the membranes of different concentrations. The surface roughness of the electrospun nanofibers fabricated from pure PCL and nHA/PCL was determined and compared using atomic force microscopy. Attenuated total reflectance Fourier transform infrared spectroscopy was used to study the chemical bonding of the composite electrospun nanofibers. Beadless nanofibers were achieved after the incorporation of nHA with a diameter of 200-700 nm. Results showed that the fiber diameter and the surface roughness of electrospun nanofibers were significantly increased after the incorporation of nHA. In contrast, the water contact angle (132°± 3.5°) was reduced for PCL membrane after addition of 10% (w/ w) nHA (112°± 3.0°). Ultimate tensile strengths of PCL membrane and 10% (w/w) nHA/PCL membrane were 25.02 ± 2.3 and 18.5 ± 4.4 MPa. A model drug tetracycline hydrochloride was successfully loaded in the membrane and the membrane demonstrated good antibacterial effects against the growth of bacteria by showing inhibition zone for E. coli (2.53 ± 0.06 cm) and B. cereus (2.87 ± 0.06 cm).

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ABSTRACT:The coastal area is absolutely essential for the purposes of resident, recreation, tourism, fisheries and agriculture as a source of socioeconomic development of local community. Some of the activities will affect the coastline changes. Coastline changes may occur due to two main factors include natural factors and also by the factor of human activities in coastal areas. Sea level rise, erosion and sedimentation are among the factors that can contribute to the changes in the coastline naturally, while the reclamation and development in coastal areas are factors of coastline changes due to human activities. Resident area and all activities in coastal areas will provide economic resources to the residents of coastal areas. However, coastline changes occur in the coastal areas will affect socio-economic for local community. A significant effect can be seen through destruction of infrastructure, loss of land, and destroy of crops. Batu Pahat is an area with significant changes of coastline. The changes of coastline from 1985 to 2013 can be determined by using topographical maps in 1985 and satellite images where the changes images are taken in 2011 and 2013 respectively. To identify the changes of risk areas, Coastal Vulnerability Index (CVI) is used to indicate vulnerability for coastal areas. This change indirectly affects the source of income in their agricultural cash crops such as oil palm and coconut. Their crops destroyed and reduced due to impact of changes in the coastline. Identification of risk coastal areas needs to be done in order for the society and local authorities to be prepared for coastline changes.