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This study aims to investigate the electric responses (complex modulus and complex impedance analysis) of hydroxyapatite/starch bone scaffold as a function of hydroxyapatite/starch proportion and the microstructural features. Hence, the non-porous and porous hydroxyapatite/starch composites were fabricated with various hydroxyapatite/starch proportions (70/30, 60/40, 50/50, 40/60, 30/70, 20/80, and 10/90 wt/wt%). Microstructural analysis of the porous hydroxyapatite/starch composites was carried out by using scanning electron microscopy. It shows that the formation of hierarchical porous microstructures with high porosity is more significant at a high starch proportion. The complex modulus and complex impedance analysis were conducted to investigate the electrical conduction mechanism of the hydroxyapatite/starch composites via dielectric spectroscopy within a frequency range from 5 MHz to 12 GHz. The electrical responses of the hydroxyapatite/starch composites are highly dependent on the frequency, material proportion, and microstructures. High starch proportion and highly porous hierarchical microstructures enhance the electrical responses of the hydroxyapatite/starch composite. The material proportion and microstructure features of the hydroxyapatite/starch composites can be indirectly reflected by the simulated electrical parameters of the equivalent electrical circuit models.

Mechanistic studies of the interaction of electromagnetic (EM) fields with biomaterials has motivated a growing need for accurate models to describe the EM behavior of biomaterials exposed to these fields. In this paper, biodegradable bone scaffolds were fabricated using Wangi rice starch and nano-hydroxyapatite (nHA). The effects of porosity and composition on the fabricated scaffold were discussed via electrical impedance spectroscopy analysis. The fabricated scaffold was subjected to an electromagnetic field within the X-band and Ku-band (microwave spectrum) during impedance/dielectric measurement. The impedance spectra were analyzed with lumped-element models. The impedance spectra of the scaffold can be embodied in equivalent circuit models composed of passive components of the circuit, i.e., resistors, inductors and capacitors. It represents the morphological, structural and chemical characteristics of the bone scaffold. The developed models describe the impedance characteristics of plant tissue. In this study, it was found that the ε′ and ε″ of scaffold composites exhibited up and down trends over frequencies for both X-band and Ku-band. The circuit models presented the lowest mean percentage errors of Z′ and Z″, i.e., 3.60% and 13.80%, respectively.

This research project was aimed to develop antibacterial hydrogel from blends of PVA and Oryza sativa L by applying freeze-thaw method (later on will refer as PVA/OS hydrogel). Agar well diffusion method was used to test the antimicrobial activity of the hydrogel against Gram-negative (E. coli) and Gram-positive bacteria (Staphy. aureus). The results indicate that PVA20/OS at pH 7 was effective as antimicrobial against both tested organisms while OS/PVA20 at pH 8 was effective for E. coli only. Based on the phytochemical test, the antimicrobial activity probably causes by the present of flavonoids content in the hydrogel. The higher PVA used in the blend’s hydrogel will increase the thickness of hydrogel. PVA40 at pH 7 and pH8 shows a good result in mechanical properties where the value of thickness is 0.750 and 0.770 mm respectively. PVA/OS blend hydrogel had good antimicrobial activity and good compatibility to form an antimicrobial hydrogel for medical purpose with the used of 20%.

Cucumber (Cucumis sativus) juice is the best rejuvenation tonic used in the folk medicine. However, during juicing, all the fibre content of the juice will be removed. Addition of inulin to the juice not only help to replace the fibre content but it also acts as prebiotic which may help to stimulate the growth of beneficial bacteria in guts. Therefore, this study focused on the effect of inulin addition in the cucumber drink on urease inhibitory and antioxidant activities, as well as on consumer acceptability. Cucumber drink was prepared using a domestic juicer and the different amounts of inulin added to the drink were based on the nutritional conditions for dietary fibre claims of a food product as a ‘source of fibre’ and ‘high fibre’ (i.e. 3 g/100 mL and 6 g/100 mL, respectively). Urease inhibitory activity was determined using phenol-hypochlorite reaction and antioxidant activity was determined using DPPH radical scavenging assay. The results show that non-fortified cucumber juice (100% without inulin) had the highest urease inhibitory and DPPH radical scavenging activities (95.1% and 38.3%, respectively). The results show that the addition of inulin to the cucumber drink does not have any impact on the urease inhibitory and DPPH radical scavenging activities. On the other hand, consumer acceptance test shows that cucumber drinks fortified with 6 g of inulin were more acceptable to the consumer based on consumers’ 9-point hedonic scale distribution.

This paper reviewed the immobilization strategy on cyclodextrin glucanotransferase (CGTase) producing Escherichia coli as whole cell biocatalyst. Biotransformation of insoluble substrate such as starch and lignocellulosic biomass with whole cell leads to the application of biological steps to chemocatalysis, which makes the whole process more effective. In this whole cell biocatalysis process, the excretion of the enzymes into the extracellular space by the cell is crucial. However, the use of free whole cell biocatalysts especially Escherichia coli often face with problem related to the cell lysis and stability. Due to that, the biotransformation process becomes inefficient. Thus, in this study the immobilization strategy was investigated to overcome the bottle necks mentioned. First, this study began with a focus in Escherichia coli, immobilization techniques, cyclodextrin, cyclodextrin glucanotransferase and recombinant Escherichia coli, in which can give a better understanding and a bigger picture in order to overcome the bottle necks mentioned. The different immobilization strategy and condition identified expected to improve the whole cell stability and reusability which lead to efficient biotransformation process. The output of the research also will elucidate the mechanism on how different immobilization material, strategy and cultural conditions improve the overall cell performance.

An atmospheric plasma system using Helium gas was developed. The effect of helium plasma treatment on skin scaffold surface was studied by scanning electron microscopy (SEM). The changes of skin scaffold surfaces before and after helium plasma treatment was recorded. The surface of skin scaffold changed with the prolonged of helium plasma treatment time. The depth of helium plasma penetration was studied using methylene blue dye staining method. The methylene blue will detect the presence or absence of an oxygen that was induced from plasma excitation. The presence of the oxygen indicated on the depth of helium plasma penetration. Results showed plasma are able to penetrate 4mm of skin scaffold after 1200 seconds of exposure.

New trend was shown the application of biodegradable plastic was used in the medicinal field especially as a template for the 3rd and 4th degree of burning is extensively studied. Currently, a bioplastic in medicinal applications for burning treatment comes from various materials based on fossil oil and synthetic chemical. Morus sp. among abundant plant and normally used for skin and inflammation treatment in traditional practices. The aim of this research is to synthesis bioplastic by using Polyvinyl alcohol (PVA) incorporates with Morus sp. leaves as the alternative of the skin template for a burning patient. With the phytochemical in the leaves such as phenolic, flavonoid and high content of antioxidant, hopefully, it will able to enhance the cell growth on the burning site without any contamination from the bacteria. 2 g Morus sp. leaves was blend with different concentration of the PVA (20%, 40%, 60%, 80%, and 100%) to produce plastic films. This mixture was stirred under constant magnetic stirring at 95°C for 1 hour. The mixtures are then pouring into a glass petri dish and dried in an oven at 50°C for 24 hours. The characterization of bioplastic is based on an antimicrobial test, tensile test, microstructure analysis using SEM and chemical composition analysed using FTIR. According to the results, a bioplastic made up from mixes Morus sp. leaves with 80% PVA has the best mechanical and antimicrobial properties. Therefore, the result showed a possible application of the film as an alternative for the medical purpose.

The purpose of this study is to investigate the relationship between the methycellulose (MC) and ethylcellulose (EC) of encapsulated C. odorata extracts (methanol and ethanol) and their antimicrobial properties against E. coli and Staphylococcus aureus. The encapsulated of C. odorata extract was prepared by solvent displacement method through dialysis tube cellulose membrane and it was freeze-dried to obtain the suspension of encapsulated C. odorata extract. Then, antimicrobial properties of encapsulated C. odorata extracts was performed by broth dilution method on target bacteria. A few drops of hydrochloric acid (HCl) were added into growth media until pH 4 to mimic the acidic conditions in human stomach. The results showed the encapsulated methylcellulose of methanol extract (MC-M) inhibit both bacteria types.

Mesoporous carbonated hydroxyapatite (Meso-CHA) is a bioceramic materials that offer good biocompatibility and bioactivity properties that suitable for bone defects or diseases treatment and therapy. Antibacterial study is very important to ensure that materials is biocompatible enough to be used on or inside the human body. The aim of this study is to investigate the antibacterial ability of the Meso-CHA (without addition of antibacterial agents) towards Escherichia coli (E. coli) bacteria. Meso-CHA samples were synthesized using chemical precipitation method where surfactant P-123 was used to introduce pores within nanoparticles structure. X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) analysis proved that pure phase of Meso-CHA was obtained. Synthesized Meso-CHA demonstrated higher pore properties (surface area = 146.92 m2g−1, pore size = 2.35 nm, and pore volume = 0.2437 cm3g−1) compared to commercial HA (surface area = 7.84 m2 g−1, pore size = 2.05 nm, and pore volume = 0.0085 cm3 g−1). The antibacterial study demonstrated that Meso-CHA has low antibacterial properties with Minimum Inhibitory Concentration (MIC) of 200 mg.ml−1 compared to HA. Carbonate ion addition into the Meso-CHA structure does not improve the antibacterial ability of the materials.