Semi-Manual Processing Of Blood Clamps Waste into Chitosan Powder

Blood clams (Anadara granosa) are endemic clams found in Southeast Asia and East Asia. Blood clams are widely consumed by the public as seafood dishes in coastal food stalls. The great potential of blood clams will increase the waste of clam shells produced. The accumulation of shellfish waste will cause pollution and reduce environmental aesthetics. The chitin content in blood clam shells can be used as chitosan. Chitosan is a polymer of -(1-4) glucosamine which is formed when the acetyl group in chitin is substituted by hydrogen to become an amine group. Chitosan has antibacterial and antifungal properties. Isolation of chitosan was carried out through the stages of demineralization, deproteination, and deacetylation. The limited use of laboratories during the pandemic is a major obstacle in the isolation process of chitosan. This study aims to process blood clam shell waste into chitosan in a simple way on a home scale. Processing includes deproteination, demineralization, and deacetylation were done using tools and materials available at home. Laboratory equipment such as beakers could be replaced with pots, the reflux process was replaced by using a cloth to filter, and measuring cups were replaced with glasses. The research used 1500 grams of blood clam shell powder and produced 1050 grams of white chitosan with a slightly hard texture

High Substitution Synthesis of Carboxymethyl Chitosan for Properties Improvement of Carboxymethyl Chitosan Films Depending on Particle Sizes

This study investigated the effect of chitosan particle sizes on the properties of carboxymethyl chitosan (CMCh) powders and films. Chitosan powders with different particle sizes (75, 125, 250, 450 and 850 µm) were used to synthesize the CMCh powders. The yield, degree of substitution (DS), and water solubility of the CMCh powders were then determined. The CMCh films prepared with CMCh based on chitosan with different particle sizes were fabricated by a solution casting technique. The water solubility, mechanical properties, and water vapor transmission rate (WVTR) of the CMCh films were measured. As the chitosan particle size decreased, the yield, DS, and water solubility of the synthesized CMCh powders increased. The increase in water solubility was due to an increase in the polarity of the CMCh powder, from a higher conversion of chitosan into CMCh. In addition, the higher conversion of chitosan was also related to a higher surface area in the substitution reaction provided by chitosan powder with a smaller particle size. As the particle size of chitosan decreased, the tensile strength, elongation at break, and WVTR of the CMCh films increased. This study demonstrated that a greater improvement in water solubility of the CMCh powders and films can be achieved by using chitosan powder with a smaller size.

Antibacterial Effect on Enterococcus Faecalis and Physical Properties of Chitosan Added Calcium Hydroxide Canal Filling Material

The aim of this study was to evaluate the antibacterial effect on Enterococcus Faecalis and physical properties of chitosan added calcium hydroxide canal filling material.<br/>Low, medium, high molecular weights of chitosan powder were mixed with calcium hydroxide canal filling material. Also, for each molecular weight group, 1.0, 2.0, 5.0 wt% of chitosan powder were added. An overnight culture of <i>E. faecalis</i> was adjusted to 1 × 10⁶ CFU/ml. For test of antibacterial effect, three different molecular weights of 2.0 wt% chitosan and three different concentrations of high molecular weight chitosan were mixed with calcium hydroxide canal filling material. The absorbance of plates was analyzed using spectrophotometer at 570 nm with a reference wavelength of 600 nm. Physical properties such as flow, film thickness and radiopacity were examined according to ISO 6876 : 2012.<br/>All molecular weight type of chitosan containing material showed inhibitory effect against E. faecalis growth compared to non-chitosan added calcium hydroxide canal filling material group (<i>p</i> < 0.05). High molecular weight chitosan containing material showed the most antibacterial effect. Also, the antibacterial effect decreased as the incorporated amount of chitosan decreased (<i>p</i> < 0.05). Every molecular weight group of material containing chitosan had a tendency for reduced flow and radiopacity, increased film thickness according to amount of chitosan. Low molecular weight of 1.0 wt% chitosan addition did not show any significant difference of physical properties compared to conventional calcium hydroxide canal filling material.<br/>In conclusion, for reinforcement of antibacterial effect against <i>E. faecalis</i> and for favorable physical properties, 2.0 wt% of chitosan adding is recommended. Considering its antibacterial effect of chitosan, further studies are required for clinical application of chitosan in endodontics and pediatric dentistry.

INFLUENCE OF IRRADIATION ON POWDER CHARACTERISTICS AND CHITOSAN SOLUTION

Chitosan is a biodegradable polymer composed of β- (1,4) -D-glucosamine linkages (deacetylated unit) and N- acetyl-D-glucosamine (acetylated unit). It is commercially produced by the deacetylation of chitin and in the food industries it is used as a stabilizer, thickener, in water treatment and easily processed into nanofibers, gels, nanoparticles and films. The objective of this work was to evaluate the effect of gamma irradiation on morphological, rheological and color properties of chitosan and gels. Chitosan samples were irradiated at the 5, 10 and 15 kGy doses and performed by scanning electron microscopy (SEM), color and rheology. SEM analyzes showed that the chitosan particles have a network agglomerated with irregular arrangements, and the irradiated samples presented smaller granules. It was observed that gamma radiation induces changes in the intensity of the tonality of the chitosan powder and gels, increasing the brown coloration. These changes are observed by the decreasing values of L * (luminosity) with increasing radiation dose and, consequently, an increase in the values of b * (brown tone), C * and h *, indicating a higher intensity of color. As for the rheological behavior, all the gels were characterized as Newtonian fluids and the irradiation altered their viscosity, leaving them less viscous.

Rapid gram-scale synthesis of Au/chitosan nanoparticles catalysts using solid mortar grinding

Owing to the abundant functional groups present in the chitosan polymer, high density catalytic tiny gold particles with greater dispersion can be anchored on the chitosan powder using simple mortar and pestle.

Comparison of bone wax and chitosan usage on post-sternotomy bone healing

Background Sternotomy is a standard approach performed in almost every surgical procedure on the heart and mediastinum. Effective hemostasis of the sternum is required to keep the operative field dry, avoid excessive blood transfusions during surgery, and prevent reoperation due to massive postoperative bleeding, which can further increase morbidity and mortality in patients. Bone wax is a mechanical hemostat commonly used after sternotomy and has been known to affect bone healing, trigger chronic inflammatory reactions, and increase the rate of infection. The application of chitosan, which has intrinsic hemostat ability, as hemostatic material is believed to improve bone healing following sternotomy. This study aimed to compare the effectiveness of bone wax and chitosan on bone healing after sternotomy. Methods Median sternotomies were performed on 2 groups of New Zealand White rabbits. Each group of 16 animals received either bone wax or chitosan powder as hemostatic material. The degree of bone healing, the number of foreign-body giant cells, and the number of osteoblasts were evaluated after 6 weeks. Results Radiographs showed that significantly more animals in the chitosan group had total sternal healing ( p = 0.033). Histopathology revealed that the number of foreign-body giant cells was significantly less ( p = 0.036) and the number of osteoblasts was significantly greater ( p < 0.0001) in the group of animals that received chitosan. Conclusion The use of chitosan as hemostatic material can promote better bone healing compared to bone wax.

Dispersion of chitosan nanoparticles stable over a wide pH range by adsorption of polyglycerol monostearate

We have developed stable chitosan colloids over a wide pH range without cross-linkers or gelling agents. The colloid was prepared using chitosan nanoparticle obtained from pulverization of bulk chitosan powder, followed by surface treatment using small amount of ascorbic acid (AA) and polyglycerol monostearate (PGMS) in water. Chitosan nanoparticles were well dispersed in a diluted AA solution due to the protonation of the chitosan chain on the surface. And then, the addition of PGMS led them to exhibit highly stable dispersion even in alkali conditions and 50 °C. The hydrodynamic diameter of the colloid was monitored using dynamic light scattering and the real image of the colloid was obtained using cryo-electron microscope measurement. This chitosan colloid will be useful for developing food ingredients or drug carrier templates that should be stable over a wide pH range.