Current Drug Delivery - Volume 20, Issue 1, 2023

Polymeric drug conjugates (PDCs) for cancer therapy have been a hot research topic for the past three decades. Successful examples of PDC conjugates have demonstrated sustained drug release action with decreased systemic toxicity and enhanced tumor retention effect (EPR) via active as well as passive targeting mechanisms. Therefore, the PDC approach has now become a keystone of the drug delivery system for cancer and other diseases. In recent years, several PDCs have successfully made up to the clinical trials. The approach aids targeted delivery of the anticancer drugs to the tumor site without disturbing the healthy cells. The selection of the over-expressed receptor and the receptor-ligand plays a vital role in designing the receptor-targeting PDC so that it is able to distinguish between the healthy cell and the tumor cell. Continuous efforts are being made in research and development toward an active targeted PDC delivery system to revolutionize cancer treatment despite the controversy built due to heterogeneity in tumor models. This review highlights the chemistry aspects involved in the preparation of PDCs that deal with novel molecular tumor targets and strategies used for the development of targeted PDCs for delivering the drug payload via active or passive targeting. Furthermore, it sheds light on the challenges faced by targeted PDCs as novel drug delivery systems.

Recently, polysaccharides have been proved to be an interesting drug delivery system as gene carriers, and natural polysaccharides have attracted more attention in the field of biomaterials due to their unique non-toxicity, good biocompatibility, and biodegradability. Compared with other polysaccharides, chitosan and dextran have more extensive and profound applications and can directly or indirectly deliver therapeutic genes. Chinese medicinal polysaccharides often do not have cationic groups and cannot directly deliver therapeutic genes. They usually need certain chemical modifications. The operation process is difficult, but better therapeutic effects are achieved. In this paper, the classification of polysaccharides and the research progress in modified polysaccharides as novel gene carriers are reviewed to provide a reference for polysaccharides as novel gene carriers in gene therapy. Moreover, efficient transfection of DNA and RNA therapeutic genes requires the development of new efficient and low-toxic vectors as well as the optimization of existing delivery vectors. Therefore, the research on polysaccharide gene vector has a long way to go and has good prospects in scientific research and biomedicine.

Liposome nanoparticles (LNPs), as a promising platform in drug delivery, combine the advantages of both liposomes and inorganic/organic nanoparticles into a single system. Both liposomes and nanoparticles have demonstrated optimized drug efficacy in the clinic. LNPs are proven to be multifunctional systems and thus utilized in various research applications (e.g., spatiotemporal control of drug release, hyperthermia, photothermal therapy, and biological imaging). The type of nanoparticles involved in LNPs largely affects the features of LNPs. Besides, diverse nanoparticles enable liposomes to overcome the defects such as poor stability, few functions, and rapid elimination from blood circulation. In this review, multiple nanoparticles materials and further prepared LNPs as well as their structure, physicochemical properties, manipulation and the latest applications in biomedical field are introduced. Future directions in advancing of LNPs are also discussed in the end.

Acne vulgaris is a universal multifactorial human skin condition of the pilosebaceous units. Although acne majorly prevails in teenagers, it is neither restricted to age group nor gender. Multifarious causative factors like Propionibacterium acnes, dysregulated sebum secretion, and androgens play an integral role in the manifestation of acne. Though abundant new chemical entities are convenient for acne therapy, none can treat this condition without compromising patient compliance. Furthermore, accessible treatment prevents the ailment and alleviates signs and symptoms with no absolute cure. So presently, despite the variety of topical formulations, the current market demands an ideal remedy to fulfill the unmet need for acne management. Extensive research has proved the upper hand of novel carrier systems over conventional formulations by substantially improving efficacy and eliminating unpleasant side effects. Lipid-based vesicular and particulate systems are promising prospects due to their closeness to the intrinsic structure of the skin, which offer delivery of the actives in a more desirable approach. This review underlines the practicability and superiority of liposomes, niosomes, transfersomes, ethosomes, cubosomes, solid lipid nanoparticles, and nanostructured lipid carriers over conventional therapies for acne. The review also highlights acne product market survey and available conventional as well as novel formulations portraying their scope in the market. In a nutshell, lipid-based vesicular and particulate systems prevail as a propitious modality for treating acne vulgaris as they conduce better penetrability, localized action, and reduce adverse effects. These systems have the ability to open a window of opportunities for effective acne alleviation.

Background: Nowadays, biomedical research has been focusing on the design and development of new drug delivery systems that provide efficient drug targeting. The molecularly imprinted polymers (MIPs) have attracted wide interest and play an indispensable role as a drug carrier. Drug delivery systems based on MIPs have been frequently cited in the literature. They are cross-linked polymers that contain binding sites according to the complementary structure of the template molecules. They possess distinctive features of structure predictability and site recognition specificity. Versatile applications of MIPs include purification, biosensing, bioseparation, artificial antibodies, and drug delivery. An ideal MIPs should include features such as biocompatibility, biodegradability, and stability. Objective: In this article, we elaborate on the historic growth, synthesis, and preparation of different MIPs and present an updated summary of recent advances in the development of new drug delivery systems which are based on this technique. Their potential to deliver drugs in a controlled and targeted manner will also be discussed. Conclusion: MIPs possess unique advantages, such as lower toxicity, fewer side effects, and good therapeutic potential. They offer administration of drugs by different routes, i.e., oral, ocular or transdermal. Despite several advantages, biomedical companies are hesitant to invest in MIPs based drug delivery systems due to the limited availability of chemical compounds.

Introduction: Clarithromycin (antibiotic), due to its narrow absorption window in the gastrointestinal tract, was taken as a model drug. Materials and Methods: Focusing on the efficient drug delivery system, floating tablets that remain buoyant over gastric fluid for 24 hrs were produced by adopting the melt mold method using beeswax, gelucire, and oleic acid. To modulate the release pattern, a different concentration of 48/16 of beeswax and gelucire was used. Results: To evaluate and characterize the final product, several tests, including the percentage recovery, in-vitro release studies, clarithromycin loading, scanning electron microscopy, differential scanning calorimeter, X-ray powder diffractometry, fourier transform infrared spectroscopy, weight variation, hardness, and friability, were carried out. Regarding the results, the encapsulation efficiency of the floating tablets was 39.5% to 59%, having weight variation with and without gelucire as 48/16 0.09525±0.0032g, and 0.09527±0.00286g to 0.0957±0.00321g, respectively. Clarithromycin release was controlled by using hydrophobic beeswax and hydrophilic gelucire 48/16. X-ray powder diffractometry, differential scanning calorimeter, and fourier transform infrared spectroscopy confirmed the absence of drug-polymer interaction, and exhibited amorphous and crystalline form of the drug after encapsulation. Drug release kinetics was determined by applying different models, such as zero-order, first-order model, Higuchi, and Korsemeyer-Pappas model. All formulations followed the Korsmeyer- Peppas model at 1.2 pH. Conclusion: Gastroretentive drug delivery systems were produced by using melt molding technique. In vitro dissolution represents the sustained release of the drug from the formulation.

Background: Caffeine abundant in coffee has a strong excitation effect on the central nerve system (CNS). Methods: To combat the adverse effects of sleep deprivation on physical and mental health, this article designed a new nasal temperature-sensitive gel loaded with caffeine, whose effects of awakening and improving cognition in sleep-deprived rats were evaluated. Results: It was found that the caffeine thermo-sensitive in situ gel (TSG) stayed in the nasal cavity for a longer time and increased the contact time between the drugs and the nasal mucosa, which made it possible for caffeine TSG to exert a lasting effect. Secondly, compared with sleep-deprived rats, those administrated with caffeine TSG were more responsive in behavioral experiments. Moreover, the antipentobarbital test proved that caffeine TSG could prolong the sleep latency and shorten the sleep time. Furthermore, caffeine TSG could significantly restore the cognitive ability by ameliorating neuronal cell injuries by upregulating brain-derived neurotrophic factor (BDNF) levels. Conclusion: Generally, caffeine TSG could quickly exert the efficacy of enhancing cognition and wakefulness, and overcome the drawbacks of frequent medications. It can potentially be used for the treatment of psychiatric disorders, such as dementia, Parkinson and Alzheimer’s disease.