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Objective To prepare an ultra-porous hydrogel capable of controlled release and investigate the drug loading, releasing, administration route and efficacy with insulin as a model drug. Methods The polymer interpenetrating network method was used to prepare ultra-porous hydrogels (SPH-IPN). Insulin was selected as a model drug to study the drug loading and efficacy. Fourier transform infrared spectroscopy and nuclear magnetic resonance carbon spectroscopy were used to investigate the structure of the gel. The swelling ratio and porosity were measured to evaluate the gel performance. Results The drug loading capacity of insulin ultra-porous hydrogel was 3.19%. The insulin-loaded freeze-dried gel exhibited good hypoglycemic effect on diabetic rats in 1−24 hours from the experimental results on rats with subcutaneous implantation. Conclusion The subcutaneously embedded lyophilized insulin ultra-porous hydrogel provided good controlled release efficacy. It maintained stable blood glucose levels within 24 hours.
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Objective:To study feasibility of preparing artificial antigen by membrane coated with hapten-carrier.To compare the Emodin-BSA membrane antigen immunogenicity and specificity against the liquid antigen.Methods:Emodin-BSA-PVDF membrane was prepared by the method that BSA was coated on PVDF membrane and the BSA was coupled with Emodin-couplint agent derivative.Rats were immunized by subcutaneous implantation.The immunogenicity and antibody specificity were characterized using Emodin-CA or Chrysophanol-CA or Physcion-CA membrane immunoassay. Results: The immunogenicity of Emodin-BSA coated membrane antigen was higher than Emodin-BSA liquid antigen;the specificity for three anthraquinones was almost the same(P>0.05). Conclusion:Emodin antiserum generated using Emodin-BSA coated membrane antigen has a high immunogenicity and specificity to Emodin.The results show it is feasible that membrane coated with hapten-carrier is used as artificial antigen.
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BACKGROUND:The form and structure of antigen-extracted xenogeneic cancel ous bone through series of physical and chemical treatment are similar to human tissue. OBJECTIVE:To detect the biocompatibility of antigen-extracted xenogeneic cancel ous bone matrix prepared by three different ways. METHODS:The antigen-extracted xenogeneic cancel ous bone scaffold materials which were prepared through physical, chemical and physical-chemical combined methods and hydroxy apatite biological ceramic materials were implanted into the dorsum subcutaneous tissue. Histological observation was done at 4, 8 and 12 weeks after surgery. The antigen-extracted xenogeneic cancel ous bone scaffold materials which were prepared through physical, chemical and physical-chemical combined methods respectively was used to culture sheep bone marrow mesenchymal stem cells for 7 days. Cel adhesion, growth, proliferation and stroma secretion were observed. RESULTS AND CONCLUSION:At 4 weeks after surgery, a strong inflammatory reaction was detected around materials in four groups. At 12 weeks, the xenogeneic bone materials prepared through physical and physical-chemical combined methods and hydroxy apatite biological ceramic materials internal pore and surrounding tissue inflammation disappeared basical y, with the presence of thimbleful inflammation cells. The material degradation was more than at 8 weeks. The xenogeneic bone materials prepared through chemical methods material internal pore and surrounding tissue inflammation stil existed, suggesting that the xenogeneic bone materials prepared through physical and physical-chemical combined methods exhibited good histocompatibility. A smal amount of orderly osteoblasts existed around hydroxy apatite biological ceramic materials and physical-chemical prepared materials, with a smal amount of bone. These suggested that there was a tendency for ectopic bone formation. The xenogeneic cancel ous bone materials prepared through physical or physical-chemical combined methods have better cytocompatibility. However, scaffold materials prepared through chemical method have poor cytocompatibility and they are not qualified for the safety standards of biological materials.
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El implante de un cardiodesfibrilador (CDI) se ha transformado hoy, en un procedimiento similar al de un marcapasos. Sin embargo, persisten inconvenientes relacionados principalmente a las vías vasculares en pacientes que portarán el equipo por muchos años, y también merecen una consideración especial los niños y jóvenes, algunos con anomalías de formación del sistema venoso. En tal sentido, puede resultar de utilidad el equipo desarrollado por Bardy y colaboradores para un implante totalmente subcutáneo, incluso sin necesidad de fluoroscopia, ya que el mismo se realiza por marcas anatómicas. El electrodo tripolar se ubica en el tejido celular subcutáneo paralelo al borde esternal izquierdo, y luego paralelo a la quinta o sexta costilla, el generador a la altura de la línea axilar. El equipo puede efectuar una descarga máxima de 80 Joule (J), pero se admite 65J para tener un margen de seguridad adecuado. La tolerancia de los pacientes fue buena. Las pruebas realizadas hasta el presente muestran factibilidad y buenos resultados. Sin duda son necesarios estudios más amplios, aleatorizados, multicéntricos y prospectivos.
The implantable cardioverter-defibrillators (ICD) is a therapy for the prevention of sudden cardiac death. Complications with implant have been associated mainly with transvenous lead insertion. Difficulties in achieving venous access can occasionally result in failed ICD implantation. Lead failures remains a major limitation and often require removal. This procedure is associated with important morbidity and mortality. To eliminate the need for venous access, Bardy et al. designed an entirely subcutaneous ICD system. The subcutaneous ICD consists of a 3-mm tripolar parasternal electrode positioned parallel to the left of the sternal midline and guided exclusively by anatomical landmarks without fluoroscopy. The pulse generator is positioned over the sixth rib between the midaxillary line and the anterior axillary line. The device delivers a maximum of only 80-J shocks. Ventricular fibrillation was converted twice in 58 of 59 patients (98%) with the delivery of 65-J shocks in two tests to ensure a margin of safety. A demand pacing at 50 beats per minute is available for 30 seconds after a shock. These studies are preliminary but the system will need to be employ in a long-term, randomized, prospective, multicenter clinical trials.
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Humans , Defibrillators, Implantable , Equipment DesignABSTRACT
Introduction: Biocompatibility of a crown-bridge material is as important as its physical and mechanical properties. It is also one of the most important factors for the long-lasting clinical success of that restoration. It directly contacts the vital prepared tooth and that is the reason it has to be nontoxic to the local tissues, such as the pulp, gingiva, or the rest of the body. Materials with different physical properties are used in the conventional fixed prosthodontic restorations. Recently, metal-free systems that are reinforced with fibers have been improved for crown and bridge restorations. These new composite systems have the advantages of both ceramic and polymer chemistry. Materials and Methods: In this research, biocompatibility of two ceramic-polymer-based prosthetic materials (Targis Dentin® and Artglass Dentin® ) was studied using a subcutaneous implantation test on rats. Initially (15 th day) mild inflammatory reactions were observed in tissues, which directly contacted the Artglass, Targis, and control tubes. These probably originated from the surgical traumas. After the 90th day of implantation, these reactions resolved and healthy, well-organized fibrous connective capsules were seen around the implants. Results: Initially (15 th day) mild inflammatory reactions were observed in tissues, which directly contacted the Artglass, Targis, and control tubes. These probably originated from the surgical traumas. After the 90 th day of implantation, these reactions resolved and healthy, well-organized fibrous connective capsules were seen around the implants. Conclusion: At the end of the study, according to the FDI and ISO-7405 standards, Targis and Artglass indicated biocompatibility with the subcutaneous connective tissue of the rat.