Ciprian Chelaru

Chemical functionalization and stabilization of type I collagen with organic tanning agents

We investigated the interactions between selected organic tanning agents and type I fibrillar collagen as a model fibrillar substrate to enable the fast direct evaluation and validation of interpretations of tanning activity. Type I fibrillar collagen (1%) as gel was used as substrate of tanning and tannic acid, resorcinol- and melamine-formaldehyde and their combination at three concentrations as crosslinking agents (tannins). To evaluate the stability of collagen during tanning, the crosslinked gels at 2.8, 4.5 and 9.0 pHs were freeze-dried as discs which were characterized by FT-IR, shrinkage temperature, enzymatic degradation and optical microscopy, and the results were validated by statistical analyses. The best stability was given by combinations between resorcinol- and melamine-formaldehyde at isoelectric pH.

Method for determination of amino acid content in protein products for medical use

METHOD FOR DETERMINATION OF AMINO ACID CONTENT IN PROTEIN PRODUCTS FOR MEDICAL USE ABSTRACT. The paper presents a method for determina

Medical Bioproducts Collagen Quantification by Hydroxyproline Determination

on of amino acid content in collagen biomaterials for medical use produced in the Collagen Department of INCDTP Division ICPI and its valida

Validation of Method for Identifying Aromatic Amines from Dyed Leather

on. The method has three stages: the fi rst consists in hydrolysing the collagen biomaterial sample down to amino acids; the second step refers to deriva

The effect of lavandula essential oils on release of niflumic acid from collagen hydrolysates

za

Collagen-Niflumic Acid Spongious Matrices for Bone Repairing

on of amino acids with N, O-bis (trimethylsilyl) trifl uoroacetamide (BSTFA) which is a silyla

Validation of method for determining the isoelectric point of protein solutions

on reagent; deriva

Validation of Method for 4-chloroaniline and 4,4'-bi-o-toluidine from Dyed Leather

zed amino acids are detected using a mass spectrometer a+ er gas chromatography. The method was validated to establish performance parameters and to check compliance with the intended purpose.

Advanced Collagen-Insulin Systems for Diabetics

The paper presents a method of quantifying collagen from medical collagen-based bioproducts obtained in the Collagen Research Department of INCDTP – Division ICPI by determining hydroxyproline. Collagen differs from usual proteins in that it contains a higher concentration of certain amino acids. Almost a third of collagen is made up of glycine, the smallest amino acid, and another third is made up of proline and hydroxyproline, the active form of proline. As hydroxyproline has been found in very few proteins other than collagen, hydroxyproline determination is used as a marker to quantify collagen levels from various medical products. Collagen is quantified by multiplying hydroxyproline content by the 6.6 factor. The proposed method was validated to establish performance parameters and to check accordance with the set goal, by determining: limit of detection, limit of quantification, selectivity, sensitivity, robustness, accuracy and reliability of the method.

Development and Characterization of Collagen - Carboxymethylcellulose Materials for Lenses

VALIDATION OF METHOD FOR IDENTIFYING AROMATIC AMINES FROM DYED LEATHER ABSTRACT. The use of chemicals to obtain semi-processed leather must be consistent with the environmental laws and regulations, which requires evaluation of toxicity in leather goods intended for consumption. The paper proposes to implement and validate an instrumental analytical method to determine azo dyes in leather. The presence of azo dyes was determined on a total of three restricted aromatic amines (4-aminobiphenyl, benzidine, 5-nitro-o-toluidine), which can be found as a result of the split of dyes used in leather dyeing. Validation parameters of gas chromatographic method were: accuracy (trueness and reliability), precision, sensitivity, limit of detection, limit of quantification, working range, linearity.