Abstract
The work reports the use of polyamidoamine dendrimers (PAMAM) and a cross-linking agent, 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide (EDC/NHS) or 4-(4,6-dimethoxy[1,3,5]triazin-2-yl)-4-methyl-morpholinium chloride (DMTMM), for the thermal stabilization of dermal bovine collagen. The efficiency of EDC/NHS/PAMAM and DMTMM/PAMAM in the cross-linking of collagen is correlated to the increase of the collagen shrinkage temperature (Ts), measured by differential scanning calorimetry (DSC). An alternative enzymatic protocol was adopted to measure the degradability of EDC/NHS/PAMAM tanned hides; these data are correlated to the thermal stability values measured by DSC. In the presence of PAMAMs, EDC/NHS provides very high stabilization of bovine dermal collagen, giving Ts of up to 95 °C, while DMTMM achieves lower stabilization. Preliminary tanning tests carried out in best reaction conditions show that EDC/NHS/PAMAM could be an interesting, environmentally-sustainable tanning system which is completely free of metals, formaldehyde, and phenols. Two new unreported dendrimeric species were synthesized and employed.
Highlights
Millions of tons of collagen are employed to produce leather goods
Variation in the shrinking temperature (Ts) of collagen was used to evaluate the thermal stability of the cross-linked materials, as previously reported [6,33,34,35]
Our studies focused only on the use of low-generation polyamidoamine dendrimers (PAMAM) dendrimers, i.e., generation 0.0 and 1.0, since it has been shown that they avoid the steric hindrance and toxicity issues which are characteristic of higher generations [28,38,39]
Summary
Millions of tons of collagen are employed to produce leather goods. The industrial process is based on the valorization of pelts (collagen) produced as waste from food manufacturing, mainly derived from cattle [1]. It is well known that an increment of cross-linking within the protein structure favors its stabilization [2,3,4,5] and enzymatic degradation resistance, which is an indication of enhanced biostability [6,7,8,9]. The nature of these cross-linking bonds depends on the specific chemical agent selected during the tanning process. The main chemical products used industrially are: i) metal complexes, to achieve coordination bonds [10,11,12]; ii) aldehydes, to form covalent bonds [13,14], iii) synthetic or natural tannins, to form ionic bonds, van der Waals interactions, and hydrogen bonds [15,16]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
