Biodegradability Assessment of Polyester Copolymers Based on Poly(ethylene adipate) and Poly(ε-caprolactone)

Abstract

Biodegradable polymers contain chains that are hydrolytically or enzymatically cleaved, resulting in soluble degradation products. Biodegradability is particularly desired in biomedical applications, in which degradation of the polymer ensures clearance from the body and eliminates the need for retrieval or explant. In this study, a homologues series of poly(ε-caprolactone)-b-poly(ethylene adipate)-b-poly(ε-caprolactone) (PCL-b-PEA-b-PCL) block copolymers, with constant PEA molar mass and different PCL sequence lengths was obtained. The starting point of these copolymers was a dihydroxy-PEA precursor with a molar mass (Mn) of 2500 g/mol. Mn values of the PCL varied between 1000 and 10,000 g/mol. Both the precursors and the copolymers were characterized using different physicochemical methods, such as: NMR, SEC, Maldi-TOFF, DSC, and ATG. The molecular characteristics of the copolymers were in a direct correlation with the sequence length of the PCL. Enzymatic degradability studies were also conducted by using cell-free extract containing Pseudomonas aeruginosa PAO1 for 10 and 21 days, and it appeared that the presence of the PEA central sequence has an important influence on the biodegradability of the copolymer samples. In fact, copolymer PCL7000-PEA2500-PCL7000 had a weight loss of around 50% after 10 days whereas the weight loss of the homopolymer PCL, with a similar Mn of 14,000 g/mol, was only 6%. The results obtained in this study indicate that these copolymer samples can be further used for the preparation of drug delivery systems with modulated biodegradability.

Development of Biodegradable Polyesters: Study of Variations in Their Morphological and Thermal Properties through Changes in Composition of Alkyl-Substituted (ε-DL) and Non-Substituted (ε-CL, EB, L-LA) Monomers

“…Another example of biodegradable polyesters ( M w up to 285 kDa) includes the use of biobased monomers, such as ethylene brassylate- b - δ -hexalactone, wherein a branched comonomer favors an amorphous arrangement, which has an impact on the mechanical properties, giving rise to possible applications in cell culture scaffolds [ 13 ]. On the other hand, triblock copolymers consisting of ethylene oxide- b - ε -caprolactone- b -γ-butyrolactone and ε -caprolactone- b -ethylene adipate- b - ε -caprolactone have also been reported; these synthesized copolyesters with M n up to 12.3 and 23.2 kDa, respectively, offer drug delivery system capabilities with specific drug-release profiles [ 14 , 15 ].…”

Mechanical Properties and Degradation Rate of Poly(Sorbitol Adipate-Co-Dioladipate) Copolymers Obtained with a Catalyst-Free Melt Polycondensation Method

“…Utilizing degradable plastics, ideally made from renewable resources, is the obvious the first step in addressing this problem. The class of polyesters with (bio)degradable qualities now dominates various application domains [ 7 , 8 , 9 ]. Different types of enzymes, such as esterase, cutinase, and lipase, are known as being highly active for the degradation of polyester-based polymers [ 7 ].…”

Amphiphilic Block Copolymers: Their Structures, and Self-Assembly to Polymeric Micelles and Polymersomes as Drug Delivery Vehicles

“…Studies have reported the significance of a few Food and Drug Administration (FDA)-approved block polymers such as poly(ɛ-caprolactone) (PCL), polylactic acid (PLA), polyglycolic acid (PGA) and polylactic acid-co-glycolic acid (PLGA) due to their biocompatibility, low cost and biodegradability [ 4 , 5 , 6 , 7 ]. A rising research interest in long-term implantable drug delivery systems for a semi-crystalline degradable polymer PLA is mentioned in the reported studies due to its good accelerating rate of bio-absorption, low cost and ease of availability.…”

“…This behavior is mostly governed by hydrophobic interactions (though in few cases other non-covalent interactions may also operate) in comparison to conventional low molecular weight surfactants [ 1 , 2 , 3 ]. However, the nature and the molecular composition of blocks and the selectivity of the solvent influences the formation and morphology of nanoaggregates [ 4 , 5 , 6 , 7 ].…”

“…Likewise, hydrophobically altered polymers are water-soluble entities which have hydrophobic groups (<2%, mole fraction) in a small amount that directly linked to the main polymer chain, and have recently attracted a lot of attention in oil exploration, paints, mineral separation, cosmetics and pharmaceutical formulations due to interesting synergistic rheological behaviour [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. Several synthetic polymers and polysaccharides have been hydrophobically modified to examine their self-assembly in water [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ].…”