Intra-Articular Injection of PLGA/Polydopamine Core-Shell Nanoparticle Attenuates Osteoarthritis Progression.

Osteoarthritis (OA) is a common joint disease characterized by progressive cartilage degeneration. Unfortunately, currently available clinical drugs are mainly analgesics and cannot alleviate the development of OA. Kartogenin (KGN) has been found to promote the differentiation of bone marrow mesenchymal stem cells (BMSCs) into chondrocytes for the treatment of cartilage damage in early OA. However, KGN, as a small hydrophobic molecule, is rapidly cleared from the synovial fluid after intra-articular injection. This study synthesized a KGN-loaded nanocarrier based on PLGA/polydopamine core/shell structure to treat OA. The fluorescence signal of KGN@PLGA/PDA-PEG-E7 nanoparticles lasted for 4 weeks, ensuring long-term sustained release of KGN from a single intra-articular injection. In addition, the polyphenolic structure of PDA enables it to effectively scavenge reactive oxygen species, and the BMSC-targeting peptide E7 (EPLQLKM) endows KGN@PLGA/PDA-PEG-E7 NPs with an effective affinity for BMSCs. As a result, the KGN@PLGA/PDA-PEG-E7 nanoparticles could effectively induce cartilage in vitro and protect the cartilage and subchondral bone in a rat ACLT model. This therapeutic strategy could also be extended to the delivery of other drugs, targeting other tissues to treat joint diseases.

[Research progress of nanomaterials for intra-articular targeted drug delivery in treatment of osteoarthritis].

Objective: To review the research progress of intra-articular targeted delivery of nanomaterials in the treatment of osteoarthritis (OA). Methods: The domestic and foreign related literature on intra-articular targeted delivery of nanomaterials for the treatment of OA was extensively reviewed, and their targeting strategies were discussed and summarized. Results: Rapid drug clearance from the joint remains a critical limitation in drug efficacy. Nanocarriers can not only significantly improve the residence profiles of drugs in the joint, but also achieve targeted delivery of drugs to specific joint tissues through active or passive targeting strategies. Conclusion: With the continuous development of various emerging tissue- or cell-specific drugs, the targeted delivery of drugs with nanomaterials promise to realize the clinical translation of these drugs in the treatment of OA.

Analysis of Cervical Sagittal Balance in Treating Cervical Spondylotic Myelopathy: 1-Level Anterior Cervical Corpectomy and Fusion Versus 2-Level Anterior Cervical Discectomy and Fusion.

BACKGROUND Anterior cervical corpectomy and fusion (ACCF), together with anterior cervical discectomy and fusion (ACDF) are both effective clinical treatments for cervical spondylotic myelopathy (CSM). Cervical sagittal balance is critical to preserving normal alignment, and is also associated with clinical outcomes. MATERIAL AND METHODS We retrospectively reviewed patients who had suffered from CSM and had undergone 1-level ACCF or 2-level ACDF surgery between December 2016 and November 2017. Forty-eight patients were identified: 25 in the ACDF group and 23 in the ACCF group. All patients received follow-up for more than 12 months. The demographic data, radiographic parameters, and clinical efficacy were compared between and within groups, both pre- and postoperatively. RESULTS Both groups acquired good clinical efficacy; both Japanese Orthopedic Association (JOA) scores and Neck Disability Index (NDI) scores improved significantly. At the final follow-up visit, patients in the ACCF and ACDF groups did not differ significantly in C2-C7 Sagittal Vertebral Axis (cSVA), T1 Pelvic Angle (TPA), Neck Tilt (NT), Thoracic Inlet Angle (TIA), JOA, or NDI scores. However, the ACDF group had a significantly larger Cobb angle and T1 Slope (T1S) than the ACCF group. The postoperative Cobb angle increased significantly only in the ACDF group, while postoperative T1S significantly increased in both ACCF and ACDF groups. CONCLUSIONS Anterior cervical surgery may change the sagittal balance in terms of T1S or Cobb angle. No significant difference was found between ACCF and ACDF in clinical outcomes or representative global sagittal parameters. ACDF achieved more lordosis improvement than ACCF, with higher T1S. Surgeons need to pay extra attention to cervical sagittal balance, rather than focusing solely on decompression.

Laser-guided transtibial technique improved single-bundle reconstruction of anterior cruciate ligament.

BACKGROUND: The transtibial tunnel technique achieves equal length reconstruction of the anterior cruciate ligament (ACL). This study aimed to investigate whether transtibial tunnel technique can achieve anatomical reconstruction of ACL. METHODS: For 25 corpses, the anterior soft tissue of the knee joint was detached so that the ligamentous surface was fully exposed, then the knee joint was fixed at 90° with an external fixator and the anterior cruciate ligament was removed. Double-sided laser technology was used to establish spatial conformation of ACL. RESULTS: The male to female ratio of the subjects was 19:6, with an average age of 59.52 ± 11.13 years. Patellar tendon length was 35.23 ± 5.10 mm, tibial eminence length and width was 15.75 ± 2.44 and 7.80 ± 1.28 mm, respectively, and femoral attachment length and width was 15.40 ± 2.17 and 8.97 ± 1.61 mm, respectively. When the flexion turned 90°, the tibial tunnel length was 31.83 ± 4.09 mm and the distance to the tibial plateau, patellar tendon, and medial collateral ligament was 16.33 ± 4.56, 10.79 ± 5.85, and 23.12 ± 5.99 mm, respectively. CONCLUSIONS: With the aid of double-sided laser technology, transtibial tunnel technique can safely achieve single-bundle reconstruction of ACL.