Sittiporn Punyanitya

Cytotoxic aporphine alkaloids from leaves and twigs of Pseuduvaria trimera (Craib).

From ethyl acetate-methanol extracts of leaves and twigs of Pseuduvaria trimera a new aporphine alkaloid; 8-hydroxy-1,4,5-trimethoxy-7-oxoaporphine or 8-hydroxyartabonatine C (1) was isolated, together with the known 1,2,3-trimethoxy-4,5-dioxo-6a,7-dehydroaporphine (ouregidione, 2). Their structures were elucidated by a combination of spectral methods; mainly 2D NMR; IR and MS. Compounds 1 and 2 exhibited cytotoxic activity with IC50 values of 26.36 ± 5.18 μM and 12.88 ± 2.49 μM, respectively, for human hepatocellular carcinoma HepG2 cells, and 64.75 ± 4.45 and 67.06 ± 3.5 μM, respectively, for human breast cancer MDA-MB231 cells. Both compounds displayed anti-cancer activity but less than that of doxorubicin; a conventional chemotherapeutic drug, the IC50 levels of which were 2.21 ± 1.72 and 1.83 ± 0.09 μM for HepG2 and MDA-MB231 cells, respectively.

Processing and Characterization of Tissue Adhesive from Rice Starch Nanocomposites

The objective of this work is make tissue adhesives agent from Thai rice starch, then test the final products for scientific and medical properties following the laws of Thai health ministry, to demonstrate that this product can be used safely, as same as the standard product. The principal raw material is pharmaceutical grade, Thai rice starch powder. The additives are hydroxyapatite (HA) nanopowder, carboxymethylcellulose, lactic acid, gelatin, polyvinylalcohol and glycerol. All materials will be mixed in distilled water under high temperature, and dried into starch tissue adhesives plate hydrogel. The final product will be kept in medical package and sent for sterilization by gamma radiation. These products will be characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD), stability in water, and adhesive bond strength test in wet environment.

Fabrication of Gelatin/Carbon Nanocomposite for Human Tissue Adhesive

Successful human tissue adhesives depend on sure parameters which cannot be matched by any one adhesive. In this work, the novel human tissue adhesive is fabricated from gelatin and coconut shell carbon nanopowder composite. Characteristics of the carbon powder and the product samples were then investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM). Mechanical characterization and tissue adhesive bonding test of the final product were also performed.

Structure and Mechanical Properties of Retrograded Rice Starch and Cow Bone Powder Composite Sponge

To study the effect of addition purified cow bone (CB) powder (20, 30, 40 and 50 wt%) in slurry suspension of retrograded rice starch (RRS). The composite sponges were used as in bone repair. The RRS-CB composite sponges were prepared from the mixture of RRS, CB and additive into distill water. The prepared samples were characterized including SEM, XRD, physical and mechanical properties. The results of optimized condition have shown the samples of 40 wt% CB that had the swelling rate as 102± 0.01%, area of expansion was 20 ± 0.03 % for 72 hours and the compressive strength was 64.35±0.05KPa. In addition, it was found that this content resulted in sufficient soft porous material, foldable by hand and self recovered body.

Effect of Hydroxyapatite Bioceramic Bodies on Subcutaneous Soft Tissue Reaction of Laboratory Rats

Hydroxyapatite (HA) is widely used in bioceramic materials for bone grafting. HA scaffolds were synthesized using solid-state reaction method. Scaffolds were prepared by milling the elements of CaCO3 and NH4H2PO4 powders. The obtained powder was pressed with uniaxial pressing into a disc shape with the dimension of 4 mm in thickness and 16.5 mm in diameter under pressures 3 MPa and then sintering the samples at difference temperatures from 1100°C to 1300°C for 3 hours. This research aimed to produce phase HA scaffolds in order to find out the effects of sintering temperature on phase contents, density, porosity, hardness and bending strength, and to use optimized condition samples study with laboratory rats’ soft tissue to evaluate the soft tissue response to the samples. Thirty-two healthy in adults’ on non-gender-specific of Wistar rats were used in this study. Optimized, sintered samples were cut and lathed into a cylindrical shape. Sixty-four samples of optimized condition were implanted and left in subcutaneous tissue for 3, 7, 14, 21, 30, 45, 90 and 180 days. XRD, XRF, Archimedes technique, Vickers hardness and bending strength, as well as light microscopy, were used for analysis. The results of optimized condition have shown the bodies of sintered sample at 1300 °C for 3 hours had the highest content of 91.02 % HA phase, and the remaining phases of 4.51 % b-TCP and 4.47 % CaO, its bulk density and strength increased with increasing temperature, the highest bulk density of 2.006 ± 0.033 g/cm3, hardness of 30.02 ± 3.23 HV, bending strength of 9.07 ± 1.15 MPa. Sample reactions to soft tissues at 180 days were mild inflammatory cells, an absence of cellular infiltration, a presence of calcification, and absence of displacement of ceramic components into surrounding host tissue. Our results concluded that the samples were nontoxic to subcutaneous tissue and biocompatibility

Absorbable suture made from rice starch

The main objective of this work is to make an absorbable monofilament suture from Thai rice starch. The improvement of the mechanical properties of Thai rice starch polymer films were achieved by addition of small amount of gelatin, carboxymethylcellulose (CMC) and carbon nanopowders. The carbon nanopowders were produced from coconut shell in our laboratory room by milling method. The incorporation of carbon nanopowders with a high aspect ratio and/or an extremely large surface area into Thai rice starch polymer films improves their mechanical performances significantly. Additionally, the black color from carbon nanopowder is easily visualized in tissue during surgery. The manufacturing processes are very simple by blending of the raw materials in hot water and then dry heating in electric oven. The final product was characterized of microstructures and mechanical properties. The resulting Thai rice starch-carbon nanocomposites possess several advantages for manufacture of sutures: 1. high water resistance that can be uses in the human body. 2. high mechanical strength that appropriate to manufacture of sutures. 3. biocompatibility and bioabsorbable. 4. low cost. 5. Eco-friendly green nanocomposites. However, the method of size designation of sutures fibers and needle attachment are the problem which restricts our suture in really applications. The investigation of knowledge and simple technology of manufacture of suture and needle attachment will be performed.

Sintering and Mechanical Properties of Dense Hydroxyapatite Nanocomposites

During recent years, there have been efforts in developing nanocrystalline bioceramics, to enhance their mechanical and biological properties for use in hard tissue engineering applications. In this work, we study the effects of some sintering additive nanopowders dopants on the properties of the sintered HA structures. Calculated quantities of silica nanopowders are incorporate as dopants into dried HA nanopowder. The mixing powders are uniaxially compacted and then sintered at 1200°C by rate-controlled sintering method in air. Compositional, microstructural, morphological and mechanical characterizations are carried out on sintered HA samples.

Fabrication and Characterization of Novel Bone Void Filler Made from Hydroxyapatite-Rice Starch Composite

The aim of this study is fabricated bone void filler (BVF) made from hydroxyapatite (HA)-rice starch (RS) composite. We provided HA derived from cockle shells and RS derived from Thai rice starch. BVF was prepared by adding the pore former method to mimic the pore structure of bones. The samples were heated at 1250°C for 3 hours. Then, the composites were prepared by dipping and coating surface of the samples with RS gel. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) confirmed that bovine bone and BVF are made of HA phase. Film of RS gel coated on surface of samples indicated that BVF without toxicity and would increased the proliferation of bone cells. Moreover, it was found that BVF after coated RS gel had water absorption value higher than before coated as 25% that exhibited a good capacity of regeneration bone.

Novel Rice Gel for Ultrasound Applications: Physical and Chemical Properties

Novel rice gels were prepared with different compositions of rice starch (RS) powder and solution of additives. The formulations of gels were composed of RS powder, liquid glycerol, and additives by aqueous solution method. Five solution with different concentration of RS powder (0.5 g, 1 g, 1.5 g, 2 g and 2.5 g). These solutions were dried in electric oven at 65°C for 4 hours. The physical and chemical properties of rice gel characterized were: turbidity, viscosity, smell, irritation, cleaning, pH and moisture content of these gels have been monitored. Results showed that 2 g of RS powder was optimized formulation which had turbidity, high viscosity, pleasant smell, non-irritation and easy to clean. The pH value of this gel was 6.92 ± 0.01 and the moisture content was 0.21 ± 0.07 % which was equivalent to commercial standard of ultrasound gel. These results concluded that the application of RS in gel ultrasound was safe and effective for replacement commercial gel ultrasound. This gel should be studied on image quality in ultrasound examination next step.

In Vivo Clinical Trial of Porous Starch-Hydroxyapatite Composite Biomaterials for Bone Regeneration

Biodegradable scaffold is an accepted and commercialized medical alternative choice for bone regeneration. In this project, we used our new invention, porous starch-Hydroxyapatite (HA) composite for in vivo clinical trial. The products were prepared from medical grade Thai rice starch mixed with high purity (>97%) HA powder from fresh cow bone, and already passed in vivo animal biocompatibility test, then processed by freeze-drying. There were 44 volunteers from orthopedic and neurosurgical division, 4 and 40 patients, respectively. The results were assessed by operative surgeons and nurses, pre-and intraoperative period, including size appropriateness, comfort handle, ease of cutting, void space filling, water stability, product weight, shelf storage, package opening, contamination risk and waste removal. All average satisfactory scales were more than 95% rating. For postoperative period, at least 6 months, the soft tissue swellings around surgical areas were resoluted about 3 days as usual healing process. There were no any symptoms or signs of infection or allergic reactions. The follow up of x-ray imaging showed well ossification about 2 months. All patients have gained good functional performance. So porous starch-HA composites biomaterial can be used for human bone and skull regeneration with completely safety and efficacy.