Ethylene brassylate-co-δ-hexalactone biobased polymers for application in the medical field: synthesis, characterization and cell culture studies

Biodegradable polyesters based on ethylene brassylate and δ-hexalactone were synthesized by ring-opening polymerization and thoroughly characterized.

Synthesis and properties of ω-pentadecalactone-co-δ-hexalactone copolymers: a biodegradable thermoplastic elastomer as an alternative to poly(ε-caprolactone)

The copolymerization of ω-pentadecalactone with δ-hexalactone creates a new kind of low glass transition polyester that shows improved biodegradability and flexibility in comparison to poly(ε-caprolactone) (PCL).

A new generation of poly(lactide/ε-caprolactone) polymeric biomaterials for application in the medical field

Thermoplastic biodegradable polymers displaying an elastomeric behavior are greatly valued for the regeneration of soft tissues and for various medical devices. In this work, terpolymers composed of ε-caprolactone (CL), D-lactide (D-LA), and L-lactide (L-LA) were synthesized. These poly(lactide-ε-caprolactone) (PLCLs) presented an elevated randomness character (R∼1), glass transition temperatures (Tg ) higher than 20°C and adjusted L-LA content. In this way, the L-LA average sequence length (/L-LA ) was reduced to below 3.62 and showed little or no crystallization capability during in vitro degradation. As a result, the obtained materials underwent homogenous degradation exhibiting KMw ranging from 0.030 to 0.066 d(-1) and without generation of crystalline remnants in advanced stages of degradation. Mechanical performance was maintained over a period of 21 days for a rac-lactide-ε-caprolactone copolymer composed of ∼85% D,L-LA and ∼15% CL and also for a terpolymer composed of ∼72% L-LA, ∼12% D-LA and ∼16% CL. Terpolymers having L-LA content from ∼60 to 70% and CL content from ∼10 to 27% were also studied. In view of the results, those materials having CL and D-LA units disrupting the microstructural arrangement of the L-LA crystallizable chains, an L-LA content <72% and a random distribution of sequences, may display proper and tunable mechanical behavior and degradation performance for a large number of medical applications. Those with a CL content from 15 to 30% will fulfill the demand of elastomeric materials of Tg higher than 20°C whereas those with a CL content from 5 to 15% might be applied as ductile stiff materials.

Posterior reversible encephalopathy syndrome as a revealing manifestation of Guillain-Barré syndrome

We report a patient with a Guillain-Barré syndrome (GBS) revealed by a posterior reversible encephalopathy syndrome (PRES). The PRES is typically associated with bilateral parieto-occipital T2 and FLAIR hyperintense MRI lesions and observed in various etiologic conditions leading to acute arterial hypertension. PRES results from a breakdown of the circulatory autoregulation, many in the posterior cerebral territories. GBS can be considered as an independent risk factor of PRES, due to acute dysautonomia and pain with consecutive arterial hypertension, as well as to cytokine production changing capillary permability. Such patients with PRES-revealed GBS may be treated with intravenous immunoglobulin therapy only after exclusion of any ischemic or hemorrhagic cerebral complications, and after control of the blood pressure and of the encephalopathic signs and symptoms.