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Massive rotator cuff tears (MRCTs) remain a challenge in orthopedic shoulder surgery. The medical implant is a feasible and effective treatment option for MRCTs. However, the complications of implant migration usually occurred in clinical trials. To address this problem, biodegradable implants from poly(L, L-lactide-co-ε-caprolactone) (PLCL) copolymers were applied to treat MRCTs and presented major clinical effects in this study. The medical implants were designed in a dented shape to clad the head of the humerus, which could prevent the migration of implants and effectively improve shoulder function in a human specimen test. The structure was tested through finite element analysis and human specimen experimentation. The appropriate ratio of PLCL constituents was confirmed by examining the degradation of PLCL implants and measuring their mechanical, physical, chemical, and biological features. Samples were characterized using a scanning electron microscope, gel permeation chromatography, mechanical test, and transmission electron microscope. It was found that PLCL5050 (segment ratio PLA:PCL = 50:50) copolymer implants possess good processability and mechanical properties, as well as an appropriate degradation time of 177 days, which could satisfy the treatment requirements of MRCTs. [ABSTRACT FROM AUTHOR]

A chemical sensor was fabricated using indium-tin-oxide (ITO) films printed on biodegradable plastic substrates. The ITO layers were printed on polylactic acid (PLA) films. To optimize the printing procedure, the thermal properties of the PLA substrate were investigated using the differential scanning calorimetry method. The structural and electrical properties of the fabricated ITO films (P-ITO) were compared with commercial sputtered ITO films (S-ITO). X-ray diffraction and Hall effect measurements were used to estimate the grain size and the carrier transportation mechanism of the ITO films. The small grain size of P-ITO was attributed to its scattering mechanism. Grain boundary scattering was shown to be dominant in the P-ITO. The chemical sensing properties were also evaluated using a droplet of methanol (20 µl), indicating that the response rate of the P-ITO film was considerably higher (650%) than that of the S-ITO film. These results were attributed to the large surface area of the P-ITO film. [ABSTRACT FROM AUTHOR]