Dual-Targeted Metal Ion Network Hydrogel Scaffold for Promoting the Integrated Repair of Tendon-Bone Interfaces.

The tendon-bone interface has a complex gradient structure vital for stress transmission and pressure buffering during movement. However, injury to the gradient tissue, especially the tendon and cartilage components, often hinders the complete restoration of the original structure. Here, a metal ion network hydrogel scaffold, with the capability of targeting multitissue, was constructed through the photopolymerization of the LHERHLNNN peptide-modified zeolitic imidazolate framework-8 (LZIF-8) and the WYRGRL peptide-modified magnesium metal-organic framework (WMg-MOF) within the hydrogel scaffold, which could facilitate the directional migration of metal ions to form a dynamic gradient, thereby achieving integrated regeneration of gradient tissues. LZIF-8 selectively migrated to the tendon, releasing zinc ions to enhance collagen secretion and promoting tendon repair. Simultaneously, WMg-MOF migrated to cartilage, releasing magnesium ions to induce cell differentiation and facilitating cartilage regeneration. Infrared spectroscopy confirmed successful peptide modification of nano ZIF-8 and Mg-MOF. Fluorescence imaging validated that LZIF-8/WMg-MOF had a longer retention, indirectly confirming their successful targeting of the tendon-bone interface. In summary, this dual-targeted metal ion network hydrogel scaffold has the potential to facilitate synchronized multitissue regeneration at the compromised tendon-bone interface, offering favorable prospects for its application in the integrated reconstruction characterized by the gradient structure.

"Early Efficacy and Safety of Unilateral Biportal Endoscopic Lumbar Interbody Fusion Versus Minimal Invasive in the Treatment of Lumbar Degenerative Diseases".

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: To compare the early clinical efficacy and radiologic outcomes between unilateral biportal endoscopic lumbar interbody fusion (ULIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). SUMMARY OF BACKGROUND DATA: Along with the continuous development of endoscopic technology, the early safety and effectiveness of ULIF technology are still unknown. MATERIALS AND METHODS: This retrospective study included 61 patients who underwent fusion surgery through ULIF or MIS-TLIF in 2021. Twenty-nine patients underwent ULIF (group A), and 32 underwent MIS-TLIF (group B). Fusion rate, bone graft volume, hidden blood loss (HBL), C-reactive protein level, operative time, Oswestry Disability Index , Visual Analog Scale score, and MacNab criteria were assessed in both groups. RESULTS: The Visual Analog Scale score for back pain in the early postoperative period was significantly lower in group A than in group B ( P <0.05). All other clinical scores showed improvement, with no significant difference between the 2 groups ( P >0.05). There was no statistically significant difference in postoperative C-reactive protein levels and fusion rates between the 2 groups ( P >0.05). However, HBL was higher and operative time was longer in group A than in group B ( P <0.05). Most importantly, there were no statistically significant differences between groups A and B in fusion rate, length of stay and bone graft volume ( P >0.05). No serious surgical complications occurred in our study. CONCLUSIONS: ULIF is a new option for lumbar fusion. Despite the drawbacks of longer operation time and higher HBL, ULIF may be a viable alternative to MIS-TLIF as technology advances.

Nanoarchitectonics of Cartilage-Targeting Hydrogel Microspheres with Reactive Oxygen Species Responsiveness for the Repair of Osteoarthritis.

Clinically, intra-articular administration can hardly achieve the truly targeted therapy, and the drugs are usually insufficient to show local and long-term therapeutic effects because of their rapid clearance. Herein, inspired by the phenomenon that bees track the scent of flowers to collect nectar, we developed cartilage-targeting hydrogel microspheres with reactive oxygen species (ROS)-responsive ability via combining the microfluidic method and photopolymerization processes to integrate cartilage-targeting peptides and ROS-responsive nanoparticles in the hydrogel matrix. The hydrogel microspheres with cartilage-targeting properties promoted better retention in the joint cavity and enhanced cellular uptake of the nanoparticles. Moreover, the ROS-responsive nanoparticles could react with osteoarthritis (OA)-induced intracellular ROS, resulting in the depolymerization of nanoparticles, which could not only eliminate excess ROS and reduce inflammation but also promote the release of dexamethasone (Dex) and kartogenin (KGN) in situ, realizing effective OA therapy. It was demonstrated that this hydrogel microsphere showed favorable ROS-responsive ability and enhanced chondrogenic differentiation as well as the downregulation of pro-inflammatory factors in vitro. Additionally, the hydrogel microspheres, similar to bees, could target and effectively repair cartilage in the OA model. Thus, the injectable hydrogel microspheres exerted an excellent potential to repair OA and may also provide an effective avenue for inflammatory bowel disease therapy.

[Bone tunnel positions in anterior cruciate ligament reconstruction evaluated by three-dimensional CT reconstruction based on Mimics software:modified transtibial versus anteromedial portal technique].

OBJECTIVE: To compare the femoral and tibial tunnel positions of anterior cruciate ligament reconstruction using the modified transtibial (MTT) technique and anteromedial (AM) portal technique. METHODS: Between January 2017 and September 2020, 78 patients with anterior cruciate ligament rupture underwent single-bundle reconstruction with the modified transtibial technique in 39 cases (group MTT) and through anteromedial approach in 39 cases (group AM). There were 25 males and 14 females in group MTT, with an average age of (37.0±2.3) years old; 27 males and 12 females in group AM, with an average age of (37.5±2.2) years old. CT scan of the affected knee was conducted one week after the surgery to measure and compare the femoral tunnels positioning (Fx, Fy), tibial tunnels positioning in the frontal plane(Tx1), tibial tunnels positioning in the sagittal plane (Ty1), and tibial tunnels positioning in the axial plane (Tx2, Ty2) in patients undergoing anterior cruciate ligament reconstruction through Mimics software. RESULTS: Three-dimensional CT reconstruction after the surgery showed that the average Fx and Fy were(25.2±2.1)% and (34.9±3.0)% respectively and the Tx1 and Ty1 were (45.5±3.3)% and (44.7± 3.0)% respectively, while the Tx2 and Ty2 were (47.0±3.0)% and (39.9±4.2)% respectively in group MTT. In group AM, the average Fx and Fy were (26.0±2.0)% and (36.1±3.9)% respectively and the Tx1 and Ty1 were (46.5±3.1)% and (45.6± 3.1)% respectively, while the Tx2 and Ty2 were (47.4±2.5)% and (39.6±3.9)% respectively. There were no statistically significant differences in the femoral and tibial tunnels between the two groups (P>0.05). Patients in both two groups obtained anatomic anterior cruciate ligament reconstruction. CONCLUSION: Both the MTT and AM technique can achieve good anatomical positioning of the femoral and tibial tunnels, without significant differences in the positioning of the bone tunnels.

Light-Responsive Micelles Loaded With Doxorubicin for Osteosarcoma Suppression.

The enhancement of tumor targeting and cellular uptake of drugs are significant factors in maximizing anticancer therapy and minimizing the side effects of chemotherapeutic drugs. A key challenge remains to explore stimulus-responsive polymeric nanoparticles to achieve efficient drug delivery. In this study, doxorubicin conjugated polymer (Poly-Dox) with light-responsiveness was synthesized, which can self-assemble to form polymeric micelles (Poly-Dox-M) in water. As an inert structure, the polyethylene glycol (PEG) can shield the adsorption of protein and avoid becoming a protein crown in the blood circulation, improving the tumor targeting of drugs and reducing the cardiotoxicity of doxorubicin (Dox). Besides, after ultraviolet irradiation, the amide bond connecting Dox with PEG can be broken, which induced the responsive detachment of PEG and enhanced cellular uptake of Dox. Notably, the results of immunohistochemistry in vivo showed that Poly-Dox-M had no significant damage to normal organs. Meanwhile, they showed efficient tumor-suppressive effects. This nano-delivery system with the light-responsive feature might hold great promises for the targeted therapy for osteosarcoma.