Nanotechnology has had a huge impact on the development of therapeutics over the last couple of decades. To date, a large number of organic nanoparticles have been developed to encapsulate and deliver therapeutic and imaging agents. These nanoparticles have allowed encapsulation and targeted release of drugs. A few nanoparticle-based drugs are already being used in patients, and several others are making excellent progress toward clinical translation. The strong pipeline of therapeutic nanoparticles is fueled by advances in novel materials and design features, new applications, and a better understanding of fundamental hurdles that limit the utility of nanoparticles. The articles in this issue of MRS Bulletin are focused on some of the significant recent advances in the use of organic nanoparticles for drug delivery and imaging.

The ability of cancer-targeted nanoparticles (NPs) to reach their site of action and evoke a desired biological response after intravenous injection is critical to achieve clinically significant in vivo efficacy. Throughout their journey in the body, NPs must successfully traverse biological environments such as blood circulation and tumor microenvironments. The interactions that occur at the interface between NPs and biological components are complex, requiring a thorough understanding of the “nano-bio” interactions to design NPs with maximal therapeutic indices. In this article, we review the challenges presented by the multiscale, important biocompartments that NPs face, describe the crucial nano-bio interactions present at each stage, and discuss potential strategies to overcome those challenges. This review suggests design considerations for NPs to optimally modulate their physicochemical properties to achieve desired biological responses, which are expected to aid chemists, engineers, and clinical scientists to design and develop highly effective delivery platforms for cancer therapy.

Research in nanotechnology-based molecular imaging and targeted drug delivery has resulted in a noticeable progress in cancer theranosis, the simultaneous application of cancer therapy and diagnosis. Theranostic nanoparticles (NPs) have been developed using diverse base materials, and organic materials are of major interest in the synthesis and preparation of these NPs. A variety of organic NPs have their own advantages, depending on the physiochemical and biological properties of the base materials. This article reviews recent developments in organic NPs, which are grouped into four major kinds of base materials: lipids, polysaccharides, peptides/proteins, and synthetic polymers. The advantageous properties of frequently used base materials and practical performance of the various organic NPs in vivo are discussed. These theranostic NPs offer new opportunities for effective cancer treatment.

This article highlights recent trends and challenges in the area of multicompartmental nanoparticles and focuses on the use of electrohydrodynamic co-jetting for preparing multicompartmental particles, fibers, and cylinders. There are many excellent reviews that have focused on various methods for the fabrication of anisotropic multifunctional particles and fibers and their respective advantages and disadvantages. In this article, we highlight recent developments in the electrohydrodynamic co-jetting approach used for the fabrication of nano- and microparticles and fibers with multifunctional characteristics. A particular focus is given to the use of this technology to control particle size and shape.

After a decade of active research, pressure is mounting for clinical translation of nanomedicines. However, to enable success in the clinic, it is important to understand the factors that can pose challenges. For example, reduction in adverse effects alone might not be enough of a driver today for clinical translation. The benchmark for clinical translation will be increased efficacy, a significant challenge to overcome if nanomedicines are developed only from a drug delivery perspective. Success in clinics will therefore require a re-examination of the design of nanomedicines, including challenging current dogmas. What can we learn from translational experience with recently approved antibody-drug conjugates, which like nanomedicines is another approach to deliver chemotherapy agents selectively to the tumors? Nanomedicines can address some of the emerging challenges in cancer chemotherapy, including heterogeneity and adaptive resistance, which can offer unique translational opportunities. This article addresses some of these themes and strategies that can facilitate translation of nanomedicines to the clinic.

The primary objective of this article is twofold: to address the key concept of topology that impacts materials science in a major way and to convey the excitement to the materials community of recent significant advances in our understanding of the important topological notions in a wide class of materials with potential technological applications. A paradigm of topology/geometry → property → functionality is emerging that goes beyond the traditional microscopic structure → property → functionality relationship. The new approach delineates the active roles of topology and geometry in design, fabrication, characterization, and predictive modeling of novel materials properties and multifunctionalities. After introducing the essentials of topology and geometry, we elucidate these concepts through a gamut of nanocarbon allotropes of de novo carbons, hierarchical self-assembled soft- and biomaterials, supramolecular assemblies, and nanoporous materials. Applications of these topological materials range from sensing, energy storage/conversion, and catalysis to nanomedicine.