Chemotherapy together with surgery and/or radiotherapy are the most common therapeutic methods for treating cancer. However, the off-target effects of chemotherapy are known to produce side effects and dose-limiting toxicities. Novel delivery platforms based on natural and synthetic polymers with enhanced pharmacokinetic and therapeutic potential for the treatment of cancer have grown tremendously over the past 10 years. Polymers can facilitate selective targeting, enhance and prolong circulation, improve delivery, and provide the controlled release of cargos through various mechanisms, including physical adsorption, chemical conjugation, and/or internal loading. Notably, polymers that are biodegradable, biocompatible, and physicochemically stable are considered to be ideal delivery carriers. This biomimetic and bio-inspired system offers a bright future for effective drug delivery with the potential to overcome the obstacles encountered. This review focuses on the barriers that impact the success of chemotherapy drug delivery as well as the recent developments based on natural and synthetic polymers as platforms for improving drug delivery for treating cancer.

Antimicrobial peptides are important candidates for developing new classes of antibiotics because of their potency against antibiotic-resistant pathogens. Current research focuses on topical applications and it is unclear how to design peptides with systemic efficacy. To address this problem, we designed two potent peptides by combining database-guided discovery with structure-based design. When bound to membranes, these two short peptides with an identical amino acid composition can adopt two distinct amphipathic structures: A classic horizontal helix (horine) and a novel vertical spiral structure (verine). Their horizontal and vertical orientations on membranes were determined by solid-state ¹⁵N NMR data. While horine was potent primarily against gram-positive pathogens, verine showed broad-spectrum antimicrobial activity. Both peptides protected greater than 80% mice from infection-caused deaths. Moreover, horine and verine also displayed significant systemic efficacy in different murine models comparable to conventional antibiotics. In addition, they could eliminate resistant pathogens and preformed biofilms. Significantly, the peptides showed no nephrotoxicity to mice after intraperitoneal or intravenous administration for 1 wk. Our study underscores the significance of horine and verine in fighting drug-resistant pathogens. Significance It is the dream of many scientists to develop antimicrobial peptides (AMPs) into potent antibiotics to combat resistant pathogens and their biofilms. However, the success is low due to limited knowledge on peptide design. Natural AMPs are diverse in sequence, activity, and source. We found a linear relationship between the averaged contents of arginine (R) and hydrophobic amino acids (Pho) of over 3,000 AMPs in the current Antimicrobial Peptide Database (http://aps.unmc.edu/AP). Based on this R–Pho relationship, we identified a peptide template and designed two representative amphipathic peptides with distinct structures and activities. Remarkably, horine and verine showed systemic efficacy in mice, but no nephrotoxicity to rodents. Our study advances peptide design and provides two antibiotics to combat drug-resistant pathogens.

The blood–brain barrier (BBB) is a highly selective and natural protective membrane that restricts the entry of therapeutic agents into the central nervous system (CNS). This restrictive nature poses a major challenge for pharmacological treatment of a wide range of CNS disorders, including neurodegenerative disorders, brain tumors, and psychiatric conditions. Many chemical drugs and biopharmaceuticals are unable to cross the BBB, and conventional drug delivery methods often fail to achieve sufficient brain concentrations, leading to reduced therapeutic efficacy and increased risk of systemic toxicity. In recent years, targeted drug delivery strategies have emerged as promising approaches to overcome the BBB and enhance the delivery of therapeutic agents to the brain. Among these, receptor-mediated transcytosis (RMT) and transporter-mediated transcytosis (TMT) are two of the most extensively studied mechanisms for transporting drugs across brain endothelial cells into the brain parenchyma. Advances in materials science and nanotechnology have facilitated the development of multifunctional carriers with optimized properties, improving drug targeting, stability, and release profiles within the brain. This review summarizes the physiological structure of the BBB and highlights recent innovations in RMT- and TMT-mediated brain drug delivery systems, emphasizing their potential not only to overcome current challenges in CNS drug development, but also to pave the way for next-generation therapies that enable more precise, effective, and personalized treatment of brain-related diseases.

The quantification of eicosanoids and their metabolites in biological samples remain an analytical challenge, even though a number of methodologies/techniques have been developed. The major difficulties encountered are related to the oxidation of eicosanoids and their low quantities in biological matrices. Among the known methodologies, liquid chromatography-mass spectrometry (LC–MS/MS) is the standard method for eicosanoid quantification in biological samples. Recently advances have improved the ability to identify and simultaneous quantitate eicosanoids in biological matrices. The present article reviews the quantitative analysis of eicosanoids in different biological matrices by LC and ultra performance liquid chromatography (UPLC)-MS/MS and discusses important aspects to be considered during the collection, sample preparation and the generation of calibration curves required for eicosanoid analysis.