Bone-Targeted Nanoparticle Drug Delivery System: An Emerging Strategy for Bone-Related Disease

Osteoarthritis is a leading cause of disability and source of societal cost in older adults. With an ageing and increasingly obese population, this syndrome is becoming even more prevalent than in previous decades. In recent years, we have gained important insights into the cause and pathogenesis of pain in osteoarthritis. The diagnosis of osteoarthritis is clinically based despite the widespread overuse of imaging methods. Management should be tailored to the presenting individual and focus on core treatments, including self-management and education, exercise, and weight loss as relevant. Surgery should be reserved for those that have not responded appropriately to less invasive methods. Prevention and disease modification are areas being targeted by various research endeavours, which have indicated great potential thus far. This narrative Seminar provides an update on the pathogenesis, diagnosis, management, and future research on osteoarthritis for a clinical audience.

Spurred by recent progress in materials chemistry and drug delivery, stimuli-responsive devices that deliver a drug in spatial-, temporal- and dosage-controlled fashions have become possible. Implementation of such devices requires the use of biocompatible materials that are susceptible to a specific physical incitement or that, in response to a specific stimulus, undergo a protonation, a hydrolytic cleavage or a (supra)molecular conformational change. In this Review, we discuss recent advances in the design of nanoscale stimuli-responsive systems that are able to control drug biodistribution in response to specific stimuli, either exogenous (variations in temperature, magnetic field, ultrasound intensity, light or electric pulses) or endogenous (changes in pH, enzyme concentration or redox gradients).

Nanoparticle-based therapeutic, prevention, and detection modalities have the potential to greatly impact how diseases are diagnosed and managed in the clinic. With the wide range of different nanomaterials available to nanomedicine researchers, the rational design of nanocarriers on an application-specific basis has become increasingly commonplace. In this review, we provide a comprehensive overview on an emerging platform: cell membrane coating nanotechnology. As one of the most fundamental units in biology, a cell carries out a wide range of functions, including its remarkable ability to interface and interact with its surrounding environment. Instead of attempting to replicate such functions via synthetic techniques, researchers are now directly leveraging naturally derived cell membranes as a means of bestowing nanoparticles with enhanced biointerfacing capabilities. This top-down technique is facile, highly generalizable, and has the potential to greatly augment the potency and safety of existing nanocarriers. Further, the introduction of a natural membrane substrate onto the surface of a nanoparticle has enabled additional applications beyond those already associated with the field of nanomedicine. Despite the relative youth of the cell membrane coating technique, there exists an impressive body of literature on the topic, which will be covered in detail in this review. Overall, there is still significant room for development, as researchers continue to refine existing workflows while finding new and exciting applications that can take advantage of this emerging technology. Cell membrane coating is an emerging nanotechnology. By cloaking nanomaterials in a layer of natural cell membrane, which can be derived from a variety of cell types, it is possible to fabricate nanoplatforms with enhanced surface functionality. This can lead to increased nanoparticle performance in complex biological environments, which can benefit applications like drug delivery, imaging, phototherapies, immunotherapies, and detoxification.