OBJECTIVE: To summarize the biomechanical research progress of biomaterials in rotator cuff injury repair and to explore how biomaterials can restore the native histological and mechanical properties of the rotator cuff. METHODS: The relevant literature at home and abroad was widely reviewed to analyze the biomechanical properties of synthetic biomaterials, naturally derived biomaterials, and tissue grafts in the repair of rotator cuff injuries. RESULTS: Synthetic biomaterials [such as poly (lactic-co-glycolic acid) and polycaprolactone] can provide initial stable mechanical support due to their adjustable mechanical properties and degradation characteristics, while naturally derived biomaterials (such as collagen and hyaluronic acid) can promote cell adhesion and tissue integration due to their biocompatibility and bioactivity. Tissue grafts exhibit significant clinical utility by providing immediate mechanical stability and promoting tendon-to-bone healing. Three-dimensional bioprinting technology provides new possibilities for personalized repair of rotator cuff injuries by precisely controlling the spatial distribution and mechanical properties of biomaterials. CONCLUSION Future studies should further optimize the design of bioprinting materials, cell sources, and scaffolds to achieve better mechanical properties and clinical efficacy of biomaterials in the repair of rotator cuff injuries.
Humans ; Rotator Cuff Injuries ; Biocompatible Materials/chemistry* ; Biomechanical Phenomena ; Tissue Scaffolds ; Rotator Cuff/surgery* ; Tissue Engineering/methods* ; Polyesters ; Polyglycolic Acid/chemistry* ; Hyaluronic Acid/chemistry* ; Collagen/chemistry* ; Lactic Acid/chemistry* ; Polylactic Acid-Polyglycolic Acid Copolymer ; Bioprinting ; Wound Healing ; Printing, Three-Dimensional ; Tendon Injuries/surgery*

Objective To study the changes of the putamen metabolites with magnetic resonance spectrum(MRS),and to explore possible underlying unrecongnised aetiological factor and pathophysiology mechanism in the central nervous system of the patients with Tourette' s syndrome.Methods Twenty-two cases of Tourette' s syndrome,and twenty-two gender and age-matched subjects ( the control subjects ) were performed on a clinical 3.0 T MRI system.Proton prob-voxel spectroscopy imaging (1H-MRS) was obtained from two sides of the putamen.The metabolites included N-acetylaspartate (NAA),creatine and phosphocreatine ( Cr),choline-containing compounds (Cho),and myoinositol ( MI ).The value of the NAA,Cr,Cho,and MI were calculated by integration of their peaks.The ratios of NAA/Cr,Cho/Cr,ML/Cr were calculated respectively.Repeated measures analysis of variance ( ANOVA ) was used to test both the value of NAA/Cr,Cho/Cr,MI/Cr of the putamen for group difference,with group as between-subjects factor and side as within-subjects factor.Results The NAA/Cr ratio in patients ( left:1.29 ± 0.13 ; right:1.34 + 0.15 ) was significantly lower than that in the control subjects ( left:1.50 ± 0.08,T =1.962,P ＜0.05 ; right:1.52 ± 0.11,T =1.865,P ＜ 0.05 ).There was no significant difference in the Cho/Cr and MI/Cr ratio between both groups.Conclusion The abnormalities of the structure and(or) function in the putamens of patients may be the one of the underlying anaetiological factors and pathophysiology mechanisms of the Tourette' s syndrome.

ObjectiveTo investigate the central nervous system mechanisms of active of movement switch in the patients with Tourette' s syndrome( TS),and to explore the possible underlying distinct neural networks for tic trigger and generation. Methods Participants were 14 patients with TS and 14 age- and gender-matched healthy volunteers with no history of physical,psychiatric or neurological disease: All patients were assessed with functional magnetic resonances imaging (fMRI)of the brain during the intermittent performance of finger-tapping switch tasks,Blood-oxygen-level dependent-fMRI was performed using a 3.0 Tesla MR.The area over which the activation was distributed was calculated,and the activation volumes were also compared between the patients with TS and the control subjects.ResultsThe regions activated in the patients with TS and in the volunteers were similar in several brain regions,including contralateral precentral and postcentral gyrus,contralateral mesia pre-front gyrus,contralateral cingulate gyrus,contralateral insula and ipsilataral cerebellum. There were also many different activation areas between the patients and the control subjects. The patients with TS demonstrated more significant and extended activation in the contralateral pre- and postcentral gyrus than the healthy volunteers.The volume of the left pre- and postcentral gyrus of the TS patients was (8.024 ±0.071 ) cm3,while the volume of the left pre-and postcentral gyrus of the control subjects was ( 6.480 ± 0.026) cm3 ( t =3.026,P ＜ 0.01 ) ; The volume of the right pre- and postcentral gyrus was (6.192 ± 0.019) cm3 in the TS cases,while there was (5.608 ±0.037) cm3 in the control subjects (t =2.752,P ＜0.05).There were significant differences in the volumes of bilateral pre- and postcetral gyrus between the TS and control subjects. The activations of conralateral thalamus without contralateral insula were found in the patients with TS. Conversely, the contralateral insula activation without thalamus activation could be found in the healthy volunteers.ConclusionThe thalamus might play an important role in the aetiological and physiopathologic mechanisms of the TS. The thalamus along with the parietal cortex,cingulate cortex and insular cortex appear to constitute a distinct neural network for tic trigger and generation.