Papers by Keyword: Hydrogel

Abstract: Polyacrylamide/polypyrrole (PAM/PPy) hydrogel was developed for the application in controlled drug delivery. PAM/PPy hydrogel was synthesized via free-radical polymerization of acrylamide using ammonium persulfate (APS) as initiator in the dispersion of PPy nanoparticle. N,N’-methylenebisacrylamide (MBA) and N,N,N’,N’-tetra-methylenediamine (TEMED) were utilized as cross-linker and accelerator, respectively. Salicylic acid (SA) was selected as a model drug in this work. The effect of PPy contents on SA-loading and releasing performances was investigated. The more PPy content was incorporated, the greater SA-loading and releasing were found. This is attributed to the increasing pore size of the PAM hydrogel when PPy nanoparticles were incorporated. Drug releasing performance from the SA-loaded PAM/PPy hydrogel were controllable under the applied potential of 1.0 volt. The research exhibits the potential of using conductive polymer hydrogel to control the drug release rate at an optimal desired level.

Abstract: Propionibacterium acnes (P. acnes) is one of skin bacteria that induce acne comedone formation. Previous studies reported that P. acnes was susceptible to alcoholic seed husk extract of Tamarindus indica L. (T. indica), no studies have been reported about the susceptibility of water extract from tamarind seed husk to P. acnes. Therefore, the objectives of this investigation were to explore the antibacterial activity of water and ethanolic seed husk extracts from T. indica (wTSH and eTSH) against P. acnes and to compare antibacterial activity of hydrogels containing wTSH and eTSH extracts against P. acnes. wTSH and eTSH extracts were reddish brown powder, and oligomeric proanthocyanidin was identified by UV-Vis spectroscopy and high performance liquid chromatography as the main ingredient in the extracts. wTSH and eTSH extracts showed the average of total phenolic compounds of 408.3±0.01 and 385.5±0.02 mg GAE/g and exhibited very strong free radical scavenging ability by DPPH assay with IC50 value of 19.6±0.2 µg/ml and 18.8±0.2 µg/ml, respectively. In addition, wTSH and eTSH extracts showed good activity against P. acnes. The minimum inhibitory concentration (MIC) of wTSH and eTSH extracts was 500 and 250 µg/ml, and the minimum bactericidal concentration (MBC) of both extracts was 500 µg/ml. In conclusion, the hydrogels which composed of 0.1% wTSH or eTSH extracts, 2% HPMC, 15% glycerin and 1% paraben concentrate, exhibited weak acid with pH 5±2, good physical stability, i.e. good spreadability with pseudoplastic flow, and also exhibited noticeable anti P. acnes activity in fluorescent resazurin assay after storage in the accelerated conditions for 3 months.

Abstract: Amoxicillin trihydrate suits to be encapsulated into a modified matrix to increase its bioavailability. In this study, the effect of drug loading methods on drug dissolution mechanism from chitosan-poly(N-vinylpyrrolidone) hydrogel with CaCO₃ as the effervescent agent has been studied. It was found that the encapsulation efficiency of in situ and post loading methods were 93% and 75%, respectively. The dissolution values were 94% and 98%, respectively for in situ and post loading. The dissolution test data was incorporated into zero-order, first-order, Higuchi and Korsmeyer-Peppas models to evaluate the kinetic and the mechanism of the drug dissolutions. The in situ loading method fits well to first-order model (R² = 0.9772), while the post loading method fits well to Higuchi model (R² = 0.9880). Based on Korsmeyer-Peppas model, the dissolution mechanism of in situ loading was Fickian diffusion (n = 0.4024), while post loading was a combination of diffusion and erosion (n = 0.5532). From the SEM images, it showed that the surface and cross-sectional of the post loading method hydrogel formed pores and pore channels, both before and after the dissolution test. Meanwhile, on the surface and the cross-sectional of in situ loading method hydrogel had pores and pore channels only after dissolution test.

Abstract: Utilization of brown algae especially in Madura, where it’s close to Surabaya, only limited for food. This become a reference for developing and increasing the potential of this algae by extracting one of the ingredients, namely alginate. This paper deals with the characterization of sodium alginate extracted from sargassum sp. using modified-purified calcium routes. The extracted sodium alginate will be further used as composite hydrogel materials and compared with commercial sodium alginate. Hereafter, the synthesized composite is expected to be bio-ink for 3d printer. Chemical composition analysis were analyzed using X-Ray Fluorosense (XRF) followed by Fourier-transform infrared spectroscopy (FTIR) analysis to identify the functional group of composite and X-Ray Diffraction (XRD). Furthermore, viscosity bath is performed to compare the viscosity of extracted and commercial one. The result shows that modified-purified calcium routes in the extraction process of sodium alginate is desirable for improving their properties. Interestingly enough, with the goal of using it as bio-ink in 3d printed fabrication, the synthesized composite shows viscosity, 300 cSt, which meets the criteria for bio-ink in 3d printer.

Abstract: The study aimed to synthesize alginate hydrogel-based composites which could be injected for medical purpose and can be cured in situ gelling after the injection process. The effect of reduced graphene oxide (r-GO) addition on Alginate /poly (vinyl alcohol) (PVA) hydrogel to physical properties were evaluated. Synthesis of hydrogel Alginate/PVA/r-GO composite was previously performed by production of r-GO using Hummer method. The composition of r-GO used in composite hydrogel was 0.4, 0.8, 1.2 and 1.6% wt. The sample was then characterized using XRD, FTIR, and analyzed perform with its curing time, injectable performance, swelling ratio, and water content.

Abstract: The topical hemostatic agents in surgery are biomaterials that very important for surgeons to stop bleeding in the complicated areas. Currently available hemostatic agents are often expensive, ineffective or raise safety concerns. Synthetic rice starch-based sponge was an inexpensive and promising alternative. In this study, we synthesized and characterized a new hemostatic agent from rice starch and investigated their use as a hemostatic material. The rice starch-based sponge having interconnected pore were synthesized via blending of the rice starch and additive of carboxymethylcellulose (CMC), polyvinyl alcohol (PVA), and glycerol in hot water, freezing and drying by vacuum sublimation with enlarged porosity and rapid swelling behavior. Characteristics of the final products were then investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM-EDS). In vivo studies using 4 rabbits with liver injury showed rice starch-based sponge blood aggregate formation as well as bulk blood coagulation inhibition. The biocompatibility tests showed that this sponge is safe and effective after follow-up for at least 6 months of animal and clinical trial.

Abstract: Tissue Engineering depends on broadly techniques to regenerate tissues and/or organ functions. To do so, tailored polymeric and/or hydrogel scaffolds may be used to ensure the appropriate regeneration. Hydrogels are suitable materials for constructing cell-laden matrices as they can be produced with incorporation of cells and rapidly cross-linked in situ through photopolymerisation reactions. Measurement of the polymerization degree, as well as resistance to compression and water retention are fundamental tests to evaluate the characteristics of hydrogels. In this work, free-radical polymerisation of poly (ethylene glycol)-dimethacrylate (PEGDMA) in UV light was assessed. Several hydrogels with different photoinitiator and water contents were produced to evaluate their influence on hydrogels behaviour. Experiments showed that variations on water and photoinitiator content induce changes in the physical and chemical behaviour of hydrogels. As it was found, water content prevents polymerisation to occur and reduces the mechanical properties of hydrogels weakening them. Furthermore, differences were found in varying water content from 15 to 30%, since this increase turned hydrogels more fragile and increase their stabilization time for water retention.

Abstract: The purpose of this study is the development and characterizations of novel polyvinyl alcohol (PVA)/polyvinyl pyrolidone (PVP) hydrogel blends. Different mixtures of the two polymeric solutions leaded to several hydrogels that were further characterized using X-ray difraction (XRD), differential thermal and thermogravimetric analysis (DTA/TGA) and Fourier transform infrared spectroscopy (FTIR). The influence of the polymer type on hydrogel hydration was also studied, by observing and comparing the samples after drying and rehydration in bidistilled water. The results revealed the maintenance of the amorphous character of the hydrogels after rehydration as well as a higher softening and decomposition temperature in direct relation with the increase of PVA content. The best wetting and swelling results were also given by the hydrogel with the highest PVA content prepared at pH 6.

Abstract: Physically cross-linked hydroxyethyl cellulose (HEC) hydrogels of different concentrations are synthesized at room temperature, and the hydrogel films are evaluated for its antimicrobial and exudate absorption properties. Results showed that all the hydrogels inherently possess antimicrobial property for all the HEC concentrations tested. The maximum water uptake is determined to be 173.8% for the 13.75% HEC hydrogel. At the same HEC concentration, the hydrogel absorbed the largest amount of exudate. The rate of diffusion in the longitudinal direction is observed to be higher, but the exudate was observed to travel generally farther in the radial direction. The diffusion coefficient model reported by Kipcak, et al. in 2014 was observed to be valid and applicable for the HEC hydrogels. Lastly, scanning electron microscopy showed the microstructure of the fibers and pores of the hydrogels.

Abstract: We developed a one-pot method for the fabrication of hydrogel-based photonic crystal (PC) materials. An array of monodisperse colloids was self-assembled within a polymer solution, which generates a visible light diffractable photonic mixture. This mixture was molded and gelated into a hydrogel PC material by freeze-thaw treatment. Drug release as well as the structure colour changing properties of the PC hydrogels were discussed, and the experiment results revealed that our one-pot design and the associated modification approach has potential in efficient fabrication of PC materials.