Recent Progress on Heparin–Protamine Particles for Biomedical Application

The Story of Ferumoxytol: Synthesis Production, Current Clinical Applications, and Therapeutic Potential

Ferumoxytol, approved by the U.S. Food and Drug Administration in 2009, is one of the intravenous iron oxide nanoparticles authorized for the treatment of iron deficiency in chronic kidney disease and end-stage renal disease. With its exceptional magnetic properties, catalytic activity, and immune activity, as well as good biocompatibility and safety, ferumoxytol has gained significant recognition in various biomedical diagnoses and treatments. Unlike most existing reviews on this topic, this review primarily focuses on the recent clinical and preclinical advances of ferumoxytol in disease treatment, spanning anemia, cancer, infectious inflammatory diseases, regenerative medicine application, magnetic stimulation for neural modulation, etc. Additionally, the newly discovered mechanisms associated with the biological effects of ferumoxytol are discussed, including its magnetic, catalytic, and immunomodulatory properties. Finally, the summary and future prospects concerning the treatment and application of ferumoxytol-based nanotherapeutics are presented.

Surface modification strategies for improved hemocompatibility of polymeric materials: a comprehensive review

Polymeric biomaterials are a widely used class of materials due to their versatile properties. However, as with all other types of materials used for biomaterials, polymers also have to interact with blood. When blood comes into contact with any foreign body, it initiates a cascade which leads to platelet activation and blood coagulation. The implant surface also has to encounter a thromboinflammatory response which makes the implant integrity vulnerable, this leads to blood coagulation on the implant and obstructs it from performing its function. Hence, the surface plays a pivotal role in the design and application of biomaterials. In particular, the surface properties of biomaterials are responsible for biocompatibility with biological systems and hemocompatibility. This review provides a report on recent advances in the field of surface modification approaches for improved hemocompatibility. We focus on the surface properties of polysaccharides, proteins, and synthetic polymers. The blood coagulation cascade has been discussed and blood - material surface interactions have also been explained. The interactions of blood proteins and cells with polymeric material surfaces have been discussed. Moreover, the benefits as well as drawbacks of blood coagulation on the implant surface for wound healing purposes have also been studied. Surface modifications implemented by other researchers to enhance as well as prevent blood coagulation have also been analyzed.

Polysaccharide-based tumor microenvironment-responsive drug delivery systems for cancer therapy

The biochemical indicators of tumor microenvironment (TME) that are different from normal tissues provide the possibility for constructing intelligent drug delivery systems (DDSs). Polysaccharides with good biocompatibility, biodegradability, and unique biological properties are ideal materials for constructing DDSs. Nanogels, micelles, organic-inorganic nanocomposites, hydrogels, and microneedles (MNs) are common polysaccharide-based DDSs. Polysaccharide-based DDSs enable precise control of drug delivery and release processes by incorporating TME-specific biochemical indicators. The classification and design strategies of polysaccharide-based TME-responsive DDSs are comprehensively reviewed. The advantages and challenges of current polysaccharide-based DDSs are summarized and the future directions of development are foreseen. The polysaccharide-based TME-responsive DDSs are expected to provide new strategies and solutions for cancer therapy and make important contributions to the realization of precision medicine.

Doxorubicin covalently conjugated heparin displays anti-cancer activity as a self-assembled nanoparticle with a low-anticoagulant effect

Heparin is a glycosaminoglycans (GAGs) member and well-known FDA-approved anticoagulant that has been widely used in the clinic for 100 years. It has also been evaluated in various fields for further clinical applications, such as in anti-cancer or anti-inflammatory therapy beyond its anticoagulant effect. Here, we sought to utilize heparin molecules as drug carriers by directly conjugating the anticancer drug doxorubicin to the carboxyl group of unfractionated heparin. Given the molecular action of doxorubicin in intercalating DNA, it is expected to be less effective when structurally combined with other molecules. However, by utilizing doxorubicin molecules to produce reactive oxygen species (ROS), we found that the heparin-doxorubicin conjugates have significant cytotoxic ability to kill CT26 tumor cells with low anticoagulant activity. Several doxorubicin molecules were bound to heparin to provide sufficient cytotoxic capability and self-assembly ability due to their amphiphilic properties. The self-assembled formation of these nanoparticles was demonstrated through DLS, SEM and TEM. The cytotoxic ROS-generating doxorubicin-conjugated heparins could inhibit tumor growth and metastasis in CT26-bearing Balb/c animal models. Our results demonstrate that this cytotoxic doxorubicin-based heparin conjugate can significantly inhibit tumor growth and metastasis, thus showing promise as a potential new anti-cancer therapeutic.

Nuclear Imaging of CAR T Immunotherapy to Solid Tumors: In Terms of Biodistribution, Viability, and Cytotoxic Effect

Immunotherapy has become a mainstay of cancer therapy. Since chimeric antigen receptor (CAR) T immunotherapy achieves unprecedented success in curing hematological malignancies, the possibility of it revolutionizing the paradigm of solid tumors has aroused increasing attention. However, the restricted accessibility to tumor parenchyma, the immunosuppressive tumor microenvironment, and antigen heterogeneity of solid tumors make it difficult to replicate its success. Therefore, dynamic evaluation of CAR T cells' tumor accessibility, intratumoral viability, and anti-tumor cytotoxicity is necessary to facilitate its translation to solid tumors. Besides, real-timely imaging above events in vivo can help evaluate therapeutic responses and optimize CAR T immunotherapy for solid tumors. Nuclear imaging, including positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging, is frequently applied for evaluating adoptive cell therapies owing to its excellent sensitivity, high tissue penetration, and great translation potential. In addition, quantitative analysis can be performed in dynamic and noninvasive patterns. This review focuses on recent advances in PET/SPECT technologies and imaging probes in monitoring CAR T cells' migration, viability, and cytotoxicity to solid tumors post-administration. Prospects of what should be done in the next stage to promote CAR T therapy's application in solid tumors are also discussed.