The combination of liposomes with polymeric scaffolds could revolutionize the current state of drug delivery technology. Although liposomes have been extensively studied as a promising drug delivery model for bioactive compounds, there still remain major drawbacks for widespread pharmaceutical application. Two approaches for overcoming the factors related to the suboptimal efficacy of liposomes in drug delivery have been suggested. The first entails modifying the liposome surface with functional moieties, while the second involves integration of pre-encapsulated drug-loaded liposomes within depot polymeric scaffolds. This attempts to provide ingenious solutions to the limitations of conventional liposomes such as short plasma half-lives, toxicity, stability, and poor control of drug release over prolonged periods. This review delineates the key advances in composite technologies that merge the concepts of depot polymeric scaffolds with liposome technology to overcome the limitations of conventional liposomes for pharmaceutical applications.
Due to limitations posed by the restrictive blood–brain barrier, conventional drug delivery systems do not provide adequate cyto‐architecture restoration and connection patterns that are essential for functional recovery in neurodegenerative disorders (NDs). Nanotechnology employs engineered materials or devices that interact with biological systems at a molecular level and could revolutionize the treatment of NDs by stimulating, responding to, and interacting with target sites to induce physiological responses while minimizing side effects. This review provides a concise discussion of the current applications of nano‐enabled drug‐delivery systems for the treatment of NDs, in particular Alzheimer's and Parkinson's diseases, and explores the future applications of nanotechnology in clinical neuroscience to develop innovative therapeutic modalities for the treatment of NDs.
Electroactive polymers (EAPs) are promising candidate materials for the design of drug delivery technologies, especially in conditions where an "on-off" drug release mechanism is required. To achieve this, EAPs such as polyaniline, polypyrrole, polythiophene, ethylene vinyl acetate, and polyethylene may be blended into responsive hydrogels in conjunction with the desired drug to obtain a patient-controlled drug release system. The "on-off" drug release mechanism can be achieved through the environmental-responsive nature of the interpenetrating hydrogel-EAP complex via (i) charged ions initiated diffusion of drug molecules; (ii) conformational changes that occur during redox switching of EAPs; or (iii) electroerosion. These release mechanisms are not exhaustive and new release mechanisms are still under investigation. Therefore, this review seeks to provide a concise incursion and critical overview of EAPs and responsive hydrogels as a strategy for advanced drug delivery, for example, controlled release of neurotransmitters, sulfosalicyclic acid from cross-linked hydrogel, and vaccine delivery. The review further discusses techniques such as linear sweep voltammetry, cyclic voltammetry, impedance spectroscopy, and chronoamperometry for the determination of the redox capability of EAPs. The future implications of the hydrogel-EAP composites include, but not limited to, application toward biosensors, DNA hybridizations, microsurgical tools, and miniature bioreactors and may be utilized to their full potential in the form of injectable devices as nanorobots or nanobiosensors.
We have isolated a cDNA clone from a human fibroblast cDNA library that contains the entire protein-coding region of a 1.1-kilobase mRNA. This mRNA encodes a 284-amino acid tropomyosin, the primary structure of which most closely resembles smooth muscle tropomyosin. Thus, the expression of both 284-amino acid muscle-type and 247-amino acid non-muscle-type tropomyosins appears to be a normal feature of human non-muscle cells. We also present evidence to suggest that this cytoskeletal tropomyosin and a human skeletal muscle P-tropomyosin are derived from a common structural gene by an alternative RNA splicing mechanism.Tropomyosins are proteins that were first isolated from skeletal muscle (1) but which, like actin, are also found in other types of muscle and most non-muscle tissues (2). In skeletal muscle, tropomyosin serves to mediate the effect of Ca2+ on the actin-myosin interaction. It does so, not by binding Ca2' directly but, through interaction with the troponins, one of which (troponin T) binds to tropomyosin at a specific site in the carboxyl-terminal region of the skeletal muscle tropomyosin molecule (3, 4). In smooth muscle and non-muscle tissues, which lack troponins, tropomyosin has a characteristic and different carboxyl-terminal primary structure (5, 6).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.