Key Engineering Materials Vol. 859

Abstract: Maclura cochinchinensis Corner or Kae Lae in Thai belongs to the Moraceae family. The plant is found in Southeast Asian countries and used in traditional medicine as a tonic agent to treat chronic fever and skin infections. Previous studies have demonstrated that plants in Moraceae family, such as Morus alba and Artocarpus lakoocha are rich source of antioxidant and anti-tyrosinase agents. Thus, the current study aimed at comparing different solvent extracts (50% ethanol, 80% ethanol, methanol by ultrasound and water decoction) of M. cochinchinensis heartwood for their antioxidant and anti-tyrosinase activities. Total phenolic content, 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, ferric reducing antioxidant power (FRAP) and anti-lipid peroxidation assays were performed to compare the antioxidant activity, whereas, Dopachrome method was performed for anti-tyrosinase activity. The results demonstrated that 80% ethanol and methanol extracts had better antioxidant activities based on EC₅₀ value of DPPH (9.96±0.21 and 9.50±0.46 μg/mL, respectively), ABTS (6.54±0.13 and 6.58±0.69 μg/mL, respectively), anti-lipid peroxidation (228.31±2.03 and 231.43±1.41 μg/mL, respectively), and anti-tyrosinase (7.60±0.29 and 7.91±0.41 μg/mL, respectively) assays. Further, 80% ethanol extract was selected to evaluate the bioactive compound using bioactivity-guided isolation. Oxyresveratrol identified as bioactive compound, exhibited higher activities than the positive controls (quercetin and kojic acid). In conclusion, 80% ethanolic M. cochinchinensis heartwood extract obtained using the ultrasound technique exhibited strong antioxidant and anti-tyrosinase effects and can be used as a potential active ingredient for cosmeceutical products. Oxyresveratrol could be used as bioactive marker for quality control of the extract and products.

Abstract: The objective of this research was to investigate the effects of emulsifier types and concentrations on the physical properties and stability of rice bran oil O/W nanoemulsions for oral administration. The nanoemulsions were formulated by using 10% of rice bran oil (RBO) as an oil phase and either single emulsifier (1,3,5% sodium caseinate (SC) or 4,6,8% polysorbate 80 (P80)) or mixed emulsifiers (1,3,5% SC and 4,6,8% P80). The nanoemulsions were prepared by Microfluidizer^® at 1,500 bar for five cycles and evaluated for droplet size, polydispersity index (PDI), zeta potential, pH, and viscosity. Their physical stability was tested under heating-cooling cycles for six cycles. The results indicated that the nanoemulsions with SC (162.50-163.48 nm) had a larger droplet size than those with P80 (90.11-105.94 nm). The concentration of SC had no significant effect on the droplet size, whereas increasing the P80 concentration resulted in a significant decrease in the droplet size. For the formulations with mixed emulsifiers, an increase in the concentration of the second emulsifier leaded to a decrease in the droplet size. All nanoemulsions had narrow size distribution (PDI < 0.2), negative charge, neutral pH value, and low viscosity. The nanoemulsions with alone SC showed a larger negative charge value as compared to those with alone P80 and mixed emulsifiers. All formulations with a single emulsifier were physically stable under heating-cooling cycles for six cycles, whereas the nanoemulsions with mixed emulsifiers showed good stability for only those with the low SC concentration (1%). The rice bran oil O/W nanoemulsions obtained from this study could be developed as oral delivery systems for further applications in the pharmaceutical and food industries.

Abstract: Resveratrol (Res) loaded nanostructured lipid carriers (NLCs) were prepared by high shear homogenization and ultrasonication technique. Caprylic/capric glyceride (IM) was used as a liquid lipid, while glyceryl monostearate (GMS), beeswax (BW), palmitic acid (PA) and myristic acid (MA) at various concentrations (5, 10, 15, and 20 %w/w) were solid lipids. Polyoxyethylene 20 sorbitan monooleate or polysorbate 80 (Tween^® 80) was use as a surfactant. The results showed that all concentration of PA and MA can be prepared the smaller particle NLC than that using GMS and BW according to the small molecule of MA and PA. The zeta potential of Res loaded NLCs were negative charge (-24.30 to -37.80 mV), which could be considered as a stable system. The stability studies revealed that NLCs with MA and PA showed a - high stability in particle size and zeta potential after storage at 40 ± 2°C /75 %RH for 3 months. These results suggested the MA and PA were suitable solid lipids for the NLCs preparation which have potential to be a nanoparticulate carrier for Res delivery.

Abstract: This study aimed to develop novel thermally crosslinked mucoadhesive nanofibers. The nanofiber patches were composed of mucoadhesive polymers which were catechol-bearing hyaluronic acid (HA-cat) and copolymer of methyl vinyl ether and maleic anhydride (Gantrez^TM, GT). Polyvinyl alcohol was used to improve the nanofiber properties. The nanofibers were prepared from a polymer mixture of 20 %wt GT, 10 %wt PVA, and 2 %wt HA-cat at different ratios using an electrospinning technique. Crosslinking process was performed by heat treatment at 130 °C for various durations. The appearances and chemical characteristics of the patch was evaluated using scanning electron microscope (SEM) and attenuated total reflectance Fourier-transformed infrared spectroscopy (ATR-FTIR), respectively. Moreover, the percentage of water insolubilization, tensile strength, and mucoadhesive property of the electrospun nanofibers were evaluated. Different polymer ratios provided identical nanoscale fibers. The patch prepared at the GT:PVA:HA-cat ration of 1:1:2 which provided the highest amount of catechol was selected. The optimal crosslinking time was 2 h under 130 °C in which the fiber diameters were not altered, and the highest percentage of water insolubilization was observed. Hydrogen and ester bond formation were established from the ATR-FTIR spectrum of the crosslinked patch. The patch could resist the force applied up to 4.82±0.46 N prior to deformation. In addition, the maximum detachment force from porcine buccal mucosa was 0.08±0.01 N. After all, the prepared electrospun mucoadhesive nanofibers may be a favorable mucoadhesive material for transmucosal drug delivery.

Abstract: In this study, 6-maleimidohexanoic acid grafted chitosan nanoparticles (MHA-CS NPs) were prepared and evaluated the efficiency of intranasal protein delivery as compared with well-known chitosan nanoparticles (CS NPs). Fluorescein isothiocyanate labelled with bovine serum albumin (FITC-BSA) was used as a model protein. The results indicated that both CS NPs and MHA-CS NPs were positively charged NPs before and after protein loading. The condition for optimal protein loading was 1:6 mass ratio of protein/NPs at 1 h incubation period. The optimal formulations of CS NPs and MHA-CS NPs were evaluated on porcine mucosa as ex vivo. The mucoadhesive and permeation properties of FITC-BSA loaded MHA-CS NPs showed a greater than FITC-BSA loaded CS NPs and FITC-BSA solution, respectively. These ex vivo studies present the potential of MHA-CS NPs as a novel carrier for intranasal protein delivery that will be a candidate for in vivo study.

Abstract: Electrospinning technique is widely investigated in medical applications such as tissue engineering scaffolds, wound dressing and drug delivery. In this study, the aligned nanofiber scaffold of Eudragit RS100 was successfully fabricated via electrospinning technique for nerve tissue engineering scaffold. The diameter distribution and degree of alignment of Eudragit RS100 nanofiber scaffold were observed by scanning electron microspore (SEM). The chemical and crystalline structure of Eudragit RS100 nanofiber scaffold were analyzed using Fourier transform infrared spectroscopy (FTIR) and Powder X-ray diffactometer (PXRD). Cell culture studies using rat Schwann cells were determined to evaluate cell proliferation cell alignment and morphology. The results implied that the diameter of fiber was in the nanometer region. The Eudragit RS100 nanofiber scaffold were in an amorphous form and its chemical structure was not destructive after the electrospinning process. The Eudragit RS100 nanofiber scaffold showed biocompatibility with rat Schwann cells and growing parallel to the aligned fibers. In conclusion, the Eudragit RS100 nanofiber scaffold may have the ability to apply to nerve tissue engineering scaffold.

Abstract: Nelumbo nucifera is a medicinal herb widely distributed in Thailand which possesses its antioxidant and antimicrobial activities. The aims of this study were to investigate the antimicrobial effects and to develop the formulations containing Nelumbo nucifera crude extracts. The crude extracts of each part of the plants, petals, pollens, receptacles and stalks were separately obtained using 95% w/w ethyl alcohol and then subjected to the phytochemical studies. The total phenolic content was quantified by using Folin-ciocalteu colorimetric method, and the antibacterial features against Staphylococcus aureus was also evaluated. The nanoemulsions incorporated with Nelumbo nucifera crude extracts were thereafter formulated. The results showed that saponins, terpenoids, flavonoids and coumarins found in petals was 184.30 ± 0.50 mg GAE/g total phenolic content which was 4-fold higher than those found in the other part of the plants. Moreover, the crude extract from petals exhibited the activity against S. aureus as indicated by the minimum bactericidal concentration (MBC) of 100 mg/mL. Moreover, the good stability of nanoemulsions consisting of 0.05% w/w petal extract was observed displaying a particle size of 400 ± 139 nm, a zeta potential of -8.09 ± 1.04 mV, and a pH value of 5.87 ± 0.07. Owing to the antimicrobial test against S.aureus, the inhibition percentage of nanoemulsions was 80.35 ± 0.106. Accordingly, this study provides the increasing of antimicrobial properties of Nelumbo nucifera crude extract when preparing into the nanoemulsions formulation. In addition, this finding could raise the value of Nelumbo nucifera which could be utilized as an alternative active ingredient for the treatment of skin bacterial infection.

Abstract: Complexation of anthocyanin has been introduced to help improved anthocyanin stability. Slightly water solubility, after forming complex of anthocyanins, represents obstacle against formulation preparation. The objective of this study is to formulate topical gel containing anthocyanin for treating oral wound. Niosomes were introduced to help delivery anthocyanins and increasing permeability. Development and evaluation of anthocyanin complex (AC) gel and anthocyanin complex niosomes (ACN) gel have been compared in physicochemical properties such as particle size, zeta potential, homogeneity, release and permeation of the gel including stability of the gel formulations. The average size of AC of ~5 nm was increased to ~100 nm after encapsulated in niosomal vesicle. Similar to the particle size, zeta potential of ACN showed greater negatively charge than the AC. The cell viability of human gingival fibroblast (HGF) exposed to AC and ACN in a concentration of 2-2000 µg/ml for 24 h showed no significantly decreased compared to the cells treated with negative control (cell culture medium solution, p > 0.05). The adhesiveness of the AC gel is stronger than the ACN gel, but after applied onto the mucosal membrane, adhesiveness detected from ACN gel were insignificantly higher than those detected from AC gel (p > 0.05). Transmission electron microscope (TEM) photograph observed AC immersed in gel-like background while ACN presented sphere-like unilamella vesicles with polymeric gel embedded in the niosomal vesicles. The AC gel and ACN gel showed a similar release pattern, but the ACN gel showed higher anthocyanin penetration than the non niosomes gel. High storage temperature affects the color of both AC gel and AC niosomes gel. Thus, our results indicate that AC gel and ACN gel provided appropriated release and permeation of active anthocyanin form, showed good stability and expressed no cytotoxicity supposed to be the proper formula for the future topical gel use.

Abstract: The aim of this study was to develop the electrospun shellac (SHL) and hydroxypropyl cellulose (HPC) blended nanofibers for drug carrier application. The effects of polymer solution and electrospinning parameters, including SHL-HPC ratio, HPC concentration, applied voltage and flow rate, on the appearance of fibers were investigated. Based on the results, electrospun fiber was not obtained when a solution of HPC alone was employed. However, the fibers would be obviously fabricated as SHL was added to the HPC solution. An increase in the SHL ratio in SHL-HPC blended solution could accordingly lead to a remarkable enhance in the fiber diameter. In addition, the continuous nanofibers with less beads were gradually formulated when the HPC concentration was increased. The electrospinning parameters seemed to be significant. The elevation of infusion rate from 0.5 to 1 mL/h would contribute to the preparation of thick fibers with the diameters enlarging from 666.9 to 843.5 nm. With the applied voltage increasing from 15 to 30 kV during the electrospinning process, the fabrication of small nanofibers with the diameters reducing from 843.5 to 741.6 nm would be conducted. In this study, monolaurin (ML), a broad antimicrobial agent, was encapsulated into the SHL-HPC carrier for the purpose of drug delivery application. Regarding the result, the loaded concentration of ML could not be enhanced by introducing HPC to the SHL fibers.

Abstract: The main objective of this study was to prepare the drug-loaded filament by hot-melt extrusion technique. Indomethacin (IND) was used as a model drug and polyvinyl alcohol (PVA) was used to produce the filament. The IND-PVA filament had clear yellow color and rough surface. Drug loading in the filament that was determined from three segments of the filament was similar, indicating that IND was homogeneously distributed in the filament.This finding was confirmed by differential scanning calorimetry and powder X-ray diffraction. In addition, thermogravimetric analysis data suggested that the drug and polymer were not degraded at temperature used in extrusion process. The filament could be further developed as dosage form or applied as starting material for 3D-printed dosage forms.