Peptide conjugation enhances the cellular co-localization, but not endosomal escape, of modular poly(acrylamide-co-methacrylic acid) nanogels

Preparation of pH-sensitive nanogels bioconjugated with shark antibodies (VNAR) for targeted drug delivery with potential applications in colon cancer therapies

Cancer is the second leading cause of death worldwide. To combat this disease, novel and specialized therapeutic systems are urgently needed. This is the first study to explore a system that combines shark variable domain (Fv) of new antigen receptor (VNAR) antibodies (hereinafter VNARs), PEGylated nanogels (pH-sensitive poly(N,N-diethylaminoethyl methacrylate, PDEAEM), and the anticancer drug 5-fluorouracil (5-FU) to explore its potential applications in colon cancer therapies. Nanogels were functionalized in a scalable reaction with an N-hydroxysuccinimide (NHS)-terminated polyethylene glycol derivative and bioconjugated with shark antibodies. Dynamic light scattering measurements indicated the presence of monodispersed nanogels (74 to 236 nm). All systems maintained the pH-sensitive capacity to increase in size as pH decreased. This has direct implications for the release kinetics of 5-FU, which was released faster at pH 5 than at pH 7.4. After bioconjugation, the ELISA results indicated VNAR presence and carcinoembryonic antigen (CEA) recognition. In vitro evaluations of HCT-116 colon cancer cells indicated that functionalized empty nanogels are not cytotoxic and when loaded with 5-FU, the cytotoxic effect of the drug is preserved. A 15% reduction in cell viability was observed after two hours of contact with bioconjugated nanogels when compared to what was observed with non-bioconjugated nanogels. The prepared nanogel system shows potential as an effective and site-specific nanocarrier with promising applications in in vivo studies of colon cancer therapies.

Self-Therapeutic Nanomaterials: Applications in Biology and Medicine

Over past decades, nanotechnology has contributed to the biomedical field in areas including detection, diagnosis, and drug delivery via opto-electronic properties or enhancement of biological effects. Though generally considered inert delivery vehicles, a plethora of past and present evidence demonstrates that nanomaterials also exude unique intrinsic biological activity based on composition, shape, and surface functionalization. These intrinsic biological activities, termed self-therapeutic properties, take several forms, including mediation of cell-cell interactions, modulation of interactions between biomolecules, catalytic amplification of biochemical reactions, and alteration of biological signal transduction events. Moreover, study of biomolecule-nanomaterial interactions offers a promising avenue for uncovering the molecular mechanisms of biology and the evolution of disease. In this review, we observe the historical development, synthesis, and characterization of self-therapeutic nanomaterials. Next, we discuss nanomaterial interactions with biological systems, starting with administration and concluding with elimination. Finally, we apply this materials perspective to advances in intrinsic nanotherapies across the biomedical field, from cancer therapy to treatment of microbial infections and tissue regeneration. We conclude with a description of self-therapeutic nanomaterials in clinical trials and share our perspective on the direction of the field in upcoming years.

Tracking the Endosomal Escape: A Closer Look at Calcein and Related Reporters

Crossing the cellular membrane and delivering active pharmaceuticals or biologicals into the cytosol of cells is an essential step in the development of nanomedicines. One of the most important intracellular processes regarding the cellular uptake of biologicals is the endolysosomal pathway. Sophisticated nanocarriers have been developed overcoming a major hurdle, the endosomal entrapment, and delivering their cargo to the required site of action. In parallel, in vitro assays have been established analyzing the performance of these nanocarriers. Among them, the release of the membrane-impermeable dye calcein has become a popular and straightforward method. It is accessible for most researchers worldwide, allows for rapid conclusions about the release potential, and enables the study of release mechanisms. This review is intended to provide an overview and guidance for scientists applying the calcein release assay. It comprises a survey of several applications in the study of endosomal escape, considerations of potential pitfalls, challenges and limitations of the assay, and a brief summary of complementary methods. Based on this review, we hope to encourage further research groups to take advantage of the calcein release assay for their own purposes and help to create a database for more efficient cross-correlations between nanocarriers. This article is protected by copyright. All rights reserved.

Advanced biomedical hydrogels: molecular architecture and its impact on medical applications

Hydrogels are cross-linked polymeric networks swollen in water, physiological aqueous solutions or biological fluids. They are synthesized by a wide range of polymerization methods that allow for the introduction of linear and branched units with specific molecular characteristics. In addition, they can be tuned to exhibit desirable chemical characteristics including hydrophilicity or hydrophobicity. The synthesized hydrogels can be anionic, cationic, or amphiphilic and can contain multifunctional cross-links, junctions or tie points. Beyond these characteristics, hydrogels exhibit compatibility with biological systems, and can be synthesized to render systems that swell or collapse in response to external stimuli. This versatility and compatibility have led to better understanding of how the hydrogel's molecular architecture will affect their physicochemical, mechanical and biological properties. We present a critical summary of the main methods to synthesize hydrogels, which define their architecture, and advanced structural characteristics for macromolecular/biological applications.

Development of Polymer-Assisted Nanoparticles and Nanogels for Cancer Therapy: An Update

With cancer remaining as one of the main causes of deaths worldwide, many studies are undergoing the effort to look for a novel and potent anticancer drug. Nanoparticles (NPs) are one of the rising fields in research for anticancer drug development. One of the key advantages of using NPs for cancer therapy is its high flexibility for modification, hence additional properties can be added to the NPs in order to improve its anticancer action. Polymer has attracted considerable attention to be used as a material to enhance the bioactivity of the NPs. Nanogels, which are NPs cross-linked with hydrophilic polymer network have also exhibited benefits in anticancer application. The characteristics of these nanomaterials include non-toxic, environment-friendly, and variable physiochemical properties. Some other unique properties of polymers are also attributed by diverse methods of polymer synthesis. This then contributes to the unique properties of the nanodrugs. This review article provides an in-depth update on the development of polymer-assisted NPs and nanogels for cancer therapy. Topics such as the synthesis, usage, and properties of the nanomaterials are discussed along with their mechanisms and functions in anticancer application. The advantages and limitations are also discussed in this article.