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Biomedical subjects

R Nudelman

Publications and source records attributed to R Nudelman.

6 recordsLinked to original sources
PubMed1995

In vivo and in vitro elimination of aliphatic polyanhydrides.

The hydrolysis and elimination processes of biopolyanhydrides has been studied using a polymer series of linear aliphatic diacids. This polymer series degrade into their monomer counterparts at about the same rate but differ in the water solubility of their degradation products. Polymers based on natural diacids of the general structure -[OOC-(CH2)x-CO]n- where x is between 4 and 12 were implanted subcutaneously in rats and the elimination of the polymers from the implantation site was observed. The in vitro hydrolysis of this polymer series was studied by monitoring the weight loss, release of monomer degradation products and the content of anhydride bonds in the polymer as a function of time. A dependence was found between the monomer solubility and the rate of polymer elimination in both in vivo and in vitro. The elimination time for polymers based on soluble monomers (x = 4-8) was 7-14 days, while the polymers based on low monomer solubility (x = 10-12) were eliminated only after 8 weeks. The in vitro degradation of polyanhydrides in the presence of several common hydrolytic enzymes found around implants did not affect polymer degradation. All polymers were biocompatible and found to be useful as carriers for drug delivery.

Anhydrides↗
PubMed1994

Chemical interactions between drugs containing reactive amines with hydrolyzable insoluble biopolymers in aqueous solutions.

Chemical reactions between drugs containing reactive amines with hydrolyzable polymers in buffer solutions were investigated. Phenylalkylamines with increasing nucleophilic reactivity were used as model drugs. Solutions of phenylalkylamines were reacted heterogeneously with representative biodegradable polyanhydride and polyester powders in various pH solutions, and the recovery of the amines from the solutions was determined. Poly(sebacic acid), a reactive polyanhydride, reacted by amide formation with the tested amines and their respective HCl salts when exposed to physiologic pH (pH 7.4). However, at pH 5.0 no interaction occurred. The aromatic polyanhydride, PCPP, and the polyesters based on lactic acid and caprolactone did react with the amine derivatives at pH 7.4, but at a slower rate. The reaction can be avoided with appropriate salt derivatives of the amines.

Amines↗
PubMed1983

C-reactive protein in pediatrics.

CRP levels have been found to be helpful in differential diagnosis and in following the clinical course and response to treatment of various disorders. Of particular interest is their value in the diagnosis of serious bacterial infections in neonates, such as meningitis, septicemia, and osteomyelitis. While no individual has been reported to be deficient in CRP, it is possible that abnormalities of CRP synthesis and function will be found. As increasing knowledge of the role of CRP accumulates, it is conceivable that CRP may acquire some therapeutic value. Increasing availability of rapid quantitative methods for CRP is likely to result in greater clinical usefulness.

Adolescent↗