Joint Diseases and Related Surgery (JDRS), the official journal of the Turkish Joint Diseases Foundation, is an international, peer-reviewed, immediate open access journal. All published articles in JDRS has been free for everyone, without embargo, since 1990.

The treatment of biofilm-associated infections and intracellular bacterial infections poses significant challenges due to the unique survival state of the bacteria.

Bone and joint tuberculosis is an extremely severe infectious disease that commonly occurs due to the primary infection of a type of mycobacteria, called Mycobacterium tuberculosis. Under the current scenario, there are very limited supplies of bone grafts available for the treatment of deceased bone, including autogenous bone and synthetic biomaterials. The present study aimed to construct a nanoscale isoniazid-loaded mineralized collagen implant, and then to explore its physicochemical properties and to investigate its biocompatibility suitable for bone and joint repair. Using type I collagen as raw material and the principle of biomimetic mineralization for self-assembly of bone tissue, a new drug-loaded mineralized collagen implant was constructed by molecular coprecipitation with isoniazid. Its surface morphology, elemental composition, and porosity were characterized by field emission scanning electron microscope (SEM), X-ray diffraction (XRD), and pycnometer. The performance of the implant was gauged by sustained release and degradation, which were studied using an ultraviolet spectrophotometer and a simulated in vivo environment. The drug loading and encapsulation rates of the implants were (6.25 ± 0.48)% and (54 ± 2.34)%, respectively. The in vitro release time of the scaffold was more than 12 weeks and the degradation performance was excellent. The scaffold was then implanted into mice, and the inflammatory reaction of local tissue was observed by Haemotoxylin and Eosin (H&E) and Masson. The in vivo evaluation in mice showed that the scaffold was biocompatible. Overall, compared with traditional drug loading systems, the isoniazid biomimetic mineralized collagen implant constructed here has better drug release performance, biodegradability, and biocompatibility. This kind of collagen implant may find potential applications in tuberculous bone and joint repair.

Bone defects, arising from various causes such as trauma, infection, tumor, surgical debridement, and congenital diseases, pose challenges to the natural self-healing process of bone tissue. Large-scale bone defects may lead to non-healing of the bone, and they need to be repaired through surgery using transplant materials. While graft materials serve as scaffolds for cell attachment and growth, infectious bone defects, like tuberculosis of the bone and joint, require anti-infective therapy concurrent with defect repair. This study aimed to construct a nano-scale drug-loaded mineralized collagen scaffold and assess its physicochemical, anti-infective, and osteogenic properties. By using isoniazid, hydroxyapatite and type I collagen, we achieved assembly through biomimetic mineralization principle and prepared a drug-loaded mineralized collagen scaffold. The scaffolds' surface morphology and composition were analyzed via field emission scanning electron microscopy (SEM) and X-ray diffraction (XRD). After sterilization, the scaffolds were co-cultured with tuberculosis bacteria to evaluate the inhibition of Mycobacterium tuberculosis growth. Additionally, the scaffolds were implanted into mice to assess degradation and drug sustained release. In a critical bone defect model in SD rats, osteogenesis was detected by Micro-CT, and biocompatibility was evaluated using HE staining of vital organs. The drug loading rate and entrapment efficiency of drug-loaded scaffolds were (6.25 ± 0.48)% and (54 ± 2.34)%, respectively. In co-culture with tuberculosis bacteria, the drug-loaded group showed a negative result in the BACTEC MIGT 960 detection system after continuous observation for more than 8 weeks, contrasting with positive results in the blank and non-drug-loaded groups. At the 8th week, acid-fast staining (AFS), auramine o staining, Micro-CT, and HE staining confirmed the drug-loaded scaffold's antibacterial properties, sustained-release capabilities, biocompatibility, and osteogenesis. Our findings demonstrate that drug-loaded biomimetic mineralized collagen scaffolds exhibit sustained-release properties, biodegradability, antibacterial efficacy, biocompatibility, and osteogenic potential. This novel drug-loaded collagen scaffold holds significant promise for the effective repair of infected bone defects.