A Review on Re-Packaging of Bisphosphonates Using Biomaterials.

The need for bone repair and insight into new regeneration therapies as well as improvement of existing regeneration routes is constantly increasing as a direct consequence of the rise in the number of trauma victims, musculoskeletal disorders, and increased life expectancy. Bisphosphonates (BPs) have emerged as a class of drugs with proven efficacy against many bone disorders. The most recent ability of this class of drugs is being explored in its anti-cancer ability. However, despite the pharmacological success, there are certain shortcomings that have circumvented this class of the drug. The mediation of biomaterials in delivering bisphosphonates has greatly helped in overcoming some of these shortcomings. This article is focused on reviewing the benefits the bisphosphonates have provided upon getting delivered via the use of biomaterials. Furthermore, the role of bisphosphonates as a potent anticancer agent is also accounted. It is witnessed that employing engineering tools in combination with therapeutics has the potential to provide solutions to bone loss from degenerative, surgical, or traumatic processes, and also aid in accelerating the healing of large bone fractures and problematic non-union fractures. The role of nanotechnology in enhancing the efficacy of the bisphosphonates is also reviewed and innovative approaches are identified.

Cell membrane coated nanocarriers - an efficient biomimetic platform for targeted therapy.

Targeted therapy approaches have become the core of modern translational science and as an intriguing field, it is the solution of the conventional drug delivery problems that were once unanswered. Traditional methods of delivering drugs and therapeutics faced issues of solubility, sustained release, not enough amount getting through the diseased site, for e.g a tumor. Various formulations of liposomes, polymers, dendrimers, etc have succeeded and made their way for clinical trials trying to enhance the pharmacokinetic and biodistribution of the drug. Many stealth coatings that include hydrophilic polymers (PEG, chitosan, polyacrylamides, etc) can act as a covering around the nanoparticle that can shield the surface from aggregation, opsonization and evade immune system, thus considered in Generally Recognized as Safe (GRAS) category. Several other polymers such as poly-2-oxazoline, polyethylene oxide, PEG-based surfactant (polysorbate-80), and zwitterionic phospholipids have also been tested for their antifouling properties. However, the polymer coating approach requires labor-intensive procedures and conjugation chemistries that often fail in mice model. Besides, due to immunogenicity and allergic reactions evoked by the PEG-coated nanoparticles, there was an urge to find biomimicking materials that can prove better as shielding agents which paved the way for cell membrane coated nanoparticles (CMCNPs) to come into the limelight. CMCNPs consist of a nanoparticle inner core covered by cell membrane that can be implicated in targeted drug delivery approaches, photothermal therapy, diagnosis or imaging making it a powerful theranostic tool. In this review, mode of preparation of CMCNPs, different sources of cell membranes (RBCs, WBCs, platelets, cancer cells, stem cells with some other unconventional sources) and nanoparticle cores that are employed have been thoroughly emphasized. In addition to this, advancements and limitations with respect to this newly emerging field have been focussed.