摘要:
A method for synthesizing a medical grade biodegradable material, poly(lactic-co-glycolic acid), copolycondensation of lactic acid and glycolic acid catalyzed by biomass creatinine. The present invention uses commercialized creatinine (a type of biomaterial organic guanidine compounds—the arginine metabolite creatinine (CR) in human body) as the catalyst and industrial lactic acid (LA, mass content 85%, aqueous solution) and glycolic acid (GA, 95%) as the monomer to synthesize the high biosafety of medical poly(lactic-co-glycolic acid) in terms of two steps polycondensation without solvent. The method of the present invention has the following characters: green technology is used, raw materials required are low in costs, operation is simple and convenient, and it is easy for industrialization; the catalyst, creatinine, used in the invention has high biocompatibility and biosafety, and no cytotoxicity; the poly(lactic-co-glycolic acid) synthesized is free of any metal and other toxic residues; Further, the molecular weight distribution for all synthesized products is narrow and the molecular weight is controllable within 1.8-17.7×104; and the poly(lactic-co-glycolic acid) synthesized is suitable for use as implantable material for hard tissue repair, surgical sutures, and the carrier for targeting drugs and controlled release drugs.
摘要:
Disclosed is a high molecular weight polylactic acid synthesized by using a method for synthesizing and catalytically-polycondensing bionic creatinine-guanidinium chloride. Creatinine is used as the material in a reaction with aqueous hydrochloric acid to synthesize a bionic creatinine-guanidinium salt catalyst, creatinine-guanidinium chloride (CR.Cl). The creatinine-guanidinium chloride synthesized is used as a catalyst, an industrial grade lactic acid (LA, 85% to 90%, aqueous solution) is used as a monomer, a solvent-free two-step polycondensation method is used to synthesize and afford metal-free and toxic residue-free polylactic acid featuring high biological safety and high molecular weight.
摘要:
A direct polycondensation method for medical biodegradable polylactic acid (PLA). The invention uses commercialized creatinine (a type of biomaterial organic guanidine compounds—the arginine metabolite creatinine in human body) as the catalyst and industrial lactic acid (mass content 85-90%, aqueous solution) as the monomer to synthesize the PLA in terms of second polycondensation without solvent. Instead of tin catalysts having cytotoxicity, the catalyst used in the invention has high biocompatibility and biosafety. The synthesized PLA does not contain any metal and other toxic components; therefore, it can be used as the carrier for targeting drugs and controlled release drugs. The green catalyst and green processing method (no solvent applied and no toxic products produced) are used to synthesize the green biodegradable PLA with high biosafety. The molecular weight distribution for all synthesized products is narrow and the molecular weight is controllable within 1.5-3.0×104.
摘要:
The present invention provides a direct polycondensation method for medical biodegradable polylactic acid (PLA) using creatinine catalyzed lactic acid. The invention uses commercialized creatinine (a type of biomaterial organic guanidine compounds—the arginine metabolite creatinine (CR) in human body) as the catalyst and industrial lactic acid (LA, mass content 85-90%, aqueous solution) as the monomer to synthesize the high biosafety of medical PLA in terms of second polycondensation without solvent (identity). Instead of tin catalysts having cytotoxicity, the catalyst used in the invention has high biocompatibility and biosafety. The synthesized PLA does not contain any metal and other toxic components; therefore, it can be used as the carrier for targeting drugs and controlled release drugs. In addition, the green catalyst and green processing method (no solvent applied and no toxic products produced) are used in the invention to synthesize the green biodegradable PLA with high biosafety. The polymerization reaction is simple and the raw materials required are low in costs, thus it is easy for industrialization. Further, the molecular weight distribution for all synthesized products is narrow and the molecular weight is controllable within 1.5-3.0×104.
摘要:
Disclosed is a high molecular weight polylactic acid synthesized by using a method for synthesizing and catalytically-polycondensing bionic creatinine-guanidinium chloride. Creatinine is used as the material in a reaction with aqueous hydrochloric acid to synthesize a bionic creatinine-guanidinium salt catalyst, creatinine-guanidinium chloride (CR.Cl). The creatinine-guanidinium chloride synthesized is used as a catalyst, an industrial grade lactic acid (LA, 85% to 90%, aqueous solution) is used as a monomer, a solvent-free two-step polycondensation method is used to synthesize and afford metal-free and toxic residue-free polylactic acid featuring high biological safety and high molecular weight.
摘要:
A method for synthesizing a medical grade biodegradable material, poly(lactic-co-glycolic acid), copolycondensation of lactic acid and glycolic acid catalyzed by biomass creatinine. The present invention uses commercialized creatinine (a type of biomaterial organic guanidine compounds—the arginine metabolite creatinine (CR) in human body) as the catalyst and industrial lactic acid (LA, mass content 85%, aqueous solution) and glycolic acid (GA, 95%) as the monomer to synthesize the high biosafety of medical poly(lactic-co-glycolic acid) in terms of two steps polycondensation without solvent. The method of the present invention has the following characters: green technology is used, raw materials required are low in costs, operation is simple and convenient, and it is easy for industrialization; the catalyst, creatinine, used in the invention has high biocompatibility and biosafety, and no cytotoxicity; the poly(lactic-co-glycolic acid) synthesized is free of any metal and other toxic residues; Further, the molecular weight distribution for all synthesized products is narrow and the molecular weight is controllable within 1.8-17.7×104; and the poly(lactic-co-glycolic acid) synthesized is suitable for use as implantable material for hard tissue repair, surgical sutures, and the carrier for targeting drugs and controlled release drugs.
摘要:
Methods, systems, and computer program products for generating a search of attachments are described. A search request based on a business template is obtained, the business template comprising a node containing an identity of an entity to which the attachment is attached and an attachment sub-node. A search request based on an attachment template is obtained, the attachment template comprising a root node referring to the attachment sub-node of the business template and a node containing an identity of the attachment. A search is performed based on the business template and the attachment template.
摘要:
A system and method may provide for defining a usage policy for an available resource of a personal computing system, and transmitting the usage policy to a market broker. The market broker may identify a match between the usage policy and a request from another computing system, and generate a notification of the match. In addition, funds may be transferred from an account associated with the other computing system to an account associated with the personal computing system based on a remote usage of the available resource by the other computing system.
摘要:
Technologies for remote device authentication include a client computing device, an identity provider, and an application server in communication over a network. The identity provider sends an authentication challenge to the client. A capability proxy of the client intercepts an authentication challenge response and retrieves one or more security assertions from a secure environment of the client computing device. The capability proxy may be an embedded web server providing an HTTP interface to platform features of the client. The client sends a resource access token based on the security assertions to the identity provider. The identity provider verifies the resource access token and authenticates the client computing device based on the resource access token in addition to user authentication factors such as username and password. The identity provider sends an authentication response to the client, which forwards the authentication response to the application server. Other embodiments are described and claimed.
摘要:
A method disclosed. The method includes receiving color data, converting the color data to grayscale data by analyzing color gamut and perceptual color differences in the color data and generating a profile based on the conversion.