Natural and Synthetic Polyesters for Musculoskeletal Tissue Repair: Experimental in Vitro and in Vivo Evaluations

Polymorphism of 1,3-cyclohexanediols: molecular structure and plastic crystal formation of cyclohexanediol isomers

Different plastic crystal formation abilities of cyclohexanediol isomers interpreted with Hirshfeld surfaces.

Molecular structure and polymorphism of a cyclohexanediol: trans-1,4-cyclohexanedimethanol

The methoxy substituent intrans-1,4-cyclohexanedimethanol stabilizes equatorial conformations, whose two polymorphs were found and characterized by DSC, FTIR, and XRD.

Tissue Engineering in Urology: Between Basic Research and Clinical Applications

Tissue engineering follows the principles of cell and tissue culture, cloning and stem cell production, and materials science to develop biological substitutes, which could repair and maintain normal function. The biomaterials must be able to control the structure and function of engineered tissue by interacting with both transplanted and host cells. Either natural or synthetic biodegradable materials have been used as cell delivery scaffolds. The stem cell field is also advancing rapidly, opening new options for regenerative medicine. In the genitourinary system, tissue engineering has been applied experimentally for the reconstitution of pelvis, ureter, bladder, urethra, penile corpora cavernosa and testis. This literature review underlines recent advances that have occurred in tissue engineering and describes their clinical repercussions, particularly in offering novel therapies in urogenital pathology.

New polymers for drug delivery systems in orthopaedics: in vivo biocompatibility evaluation

The use of biodegradable polymers for drug delivery systems excluded the need for a second operation to remove the carrier. However, the development of an avascular fibrous capsule, reducing drug release, has raised concern about these polymers in terms of tissue-implant reaction. Five novel polymers were evaluated in vivo after implantation in the rat dorsal subcutis and compared to the reference polycaprolactone (PCL). Poly(cyclohexyl-sebacate) (PCS), poly(L-lactide-b-1,5-dioxepan-2-one-b-L-lactide) (PLLA-PDXO-PLLA), two 3-hydroxybutyrate-co-3-hydroxyvalerate copolymers (D400G and D600G), and a poly(organo)phosphazene (POS-PheOEt:Imidazole) specimens were histologically evaluated in terms of the inflammatory tissue thickness and vascular density at 4 and 12 weeks from surgery. The highest values of inflammatory tissue thickness were observed in D600G (P < 0.01), PCS (P < 0.001) and PLLA-PDXO-PLLA (P < 0.001) at 4 weeks, while POP-PheOEt:Imidazole showed the lowest value of inflammatory tissue thickness (P < 0.05) at 12 weeks. D400G, D600G, PLLA-PDXO-PPLA and POP-PheOEt:Imidazole showed higher (P < 0.001) values of vascular density near the implants in comparison to PCL at 4 weeks. Finally, D400G and D600G increased their vessel densities while POP-PheOEt:Imidazole and the synthetic polyester PLLA-PDXO-PLLA presented similar vessel density values during experimental times. These different behaviours to improve neoangiogenesis without severe inflammatory tissue-responses could be further investigated with drugs in order to obtain time-programmable drug delivery systems for musculoskeletal therapy.