3D-bioimplants mimicking the structure and function of spine units for the treatment of spinal tuberculosis

Recent Advances in Nanotechnology-Based Strategies for Bone Tuberculosis Management

Bone tuberculosis, an extrapulmonary manifestation of tuberculosis, presents unique treatment challenges, including its insidious onset and complex pathology. While advancements in anti-tubercular therapy have been made, the efficacy is often limited by difficulties in achieving targeted drug concentrations and avoiding systemic toxicity. The intricate bone structure and presence of granulomas further impede effective drug delivery. Nano-drug delivery systems have emerged as a promising alternative, offering the enhanced targeting of anti-tubercular drugs. These systems, characterized by their minute size and adaptable surface properties, can be tailored to improve drug solubility, stability, and bioavailability, while also responding to specific stimuli within the bone TB microenvironment for controlled drug release. Nano-drug delivery systems can encapsulate drugs for precise delivery to the infection site. A significant innovation is their integration with prosthetics or biomaterials, which aids in both drug delivery and bone reconstruction, addressing the infection and its osteological consequences. This review provides a comprehensive overview of the pathophysiology of bone tuberculosis and its current treatments, emphasizing their limitations. It then delves into the advancements in nano-drug delivery systems, discussing their design, functionality, and role in bone TB therapy. The review assesses their potential in preclinical research, particularly in targeted drug delivery, treatment efficacy, and a reduction of side effects. Finally, it highlights the transformative promise of nanotechnology in bone TB treatments and suggests future research directions in this evolving field.

Development of tetracycline-modified nanoparticles for bone-targeted delivery of anti-tubercular drug

Background: Since the poor response to existing anti-tuberculosis drugs and low drug concentration in local bone tissues, the traditional drug therapy does not result in satisfactory treatment of osteoarticular tuberculosis. Thus, we report a rifapentine release system with imparted bone targeting potential using tetracycline (TC) -modified nanoparticles (NPs). Methods: TC was conjugated to PLGA-PEG copolymer via a DCC/NHS technique. Rifapentine-loaded NPs were prepared by premix membrane emulsification technique. The resulting NPs were characterized in terms of physicochemical characterization, hemolytic study, cytotoxicity, bone mineral binding ability, in vitro drug release, stability test and antitubercular activity. The pharmacokinetic and biodistribution studies were also performed in mice. Results: Rifapentine loaded TC-PLGA-PEG NPs were proved to be 48.8 nm in size with encapsulation efficiency and drug loading of 83.3% ± 5.5% and 8.1% ± 0.4%, respectively. The release of rifapentine from NPs could be maintained for more than 60 h. Most (68.0%) TC-PLGA-PEG NPs could bind to HAp powder in vitro. The cellular studies revealed that NPs were safe for intravenous administration. In vivo evaluations also revealed that the drug concentration of bone tissue in TC-PLGA-PEG group was significantly higher than that in other groups at all time (p < 0.05). Both NPs could improve pharmacokinetic parameters without evident organ toxicity. The minimal inhibitory concentration of NPs was 0.094 μg/mL, whereas this of free rifapentine was 0.25 μg/mL. Conclusion: Rifapentine loaded TC-PLGA-PEG NPs could increase the amount of rifapentine in bone tissue, prolong drug release in systemic circulation, enhance anti-tuberculosis activity, and thereby reducing dose and frequency of drug therapy for osteoarticular tuberculosis.