A Novel Targeting Drug Delivery System Based on Self-Assembled Peptide Hydrogel

In the last two decades, 5-fluorouracil (5-FU) is widely used in clinical practice to inhibit the fibroblasts to proliferate and improve the success rate of glaucoma-filtering surgery, but 5-FU has many toxic effects to normal ocular tissues. The self-assembled peptide hydrogels may serve as a new class of biomaterials for applications including tissue engineering and drug delivery. How to deliver 5-FU quickly and precisely to the target sites of ocular tissue by a self-assembled peptide hydrogel remains unexplored. RGD (arginine-glycine-aspartic acid) sequence is cell attachment site in extracellular matrix (ECM). Thus, If the self-assembled peptide hydrogel containing the RGD sequence that act as a specific attachment site for the proliferated fibroblasts adhesion could be designed, after integrated 5-FU, a novel targeting drug delivery system will be put into practice in the future.

Phytocompounds and lipid-based drug delivery system for neurodegenerative diseases

Across the annals of time,organic molecules sourced from nature have found innumerable uses within the realms of healthcare,pharmaceuticals,and the study of living organisms.This abundant source of natural compounds has exhibited immense promise in the cure of diverse ailments,mainly neurodegenerative diseases owing to their minimum toxic and adverse effects.However,different challenges exist with phytocompounds from plants such as poor permeation,poor solubility(water/lipid),unsteadiness under extremely acidic pH conditions,and lack of targeting specificity.Furthermore,as a result of the existence of blood-brain barrier membrane and inconvenient pharmacokinetics characteristics of phytocompounds,their passage into the brain is constrained.In order to address this issue and augment the transportation of medications into the brain at a therapeutically effective level,it is imperative to formulate an innovative and pragmatic strategy.Many papers have shown that nanoformulations containing phytocompounds(resveratrol,quercetin,ferulic acid,curcumin,berberine,etc.)effectively improved many neurodegenerative diseases such as Parkinson’s,Alzheimer’s and Huntington’s diseases.This study provides an overview of phytocompounds that are used in nanosized lipid drug delivery systems.These systems are categorized according to lipid types and preparation techniques used in the formulation.Some studies regarding these systems and phytocompounds are also summarized.

A review on phospholipids and their main applications in drug delivery systems

Phospholipids have the characteristics of excellent biocompatibility and a especial amphiphilicity.These unique properties make phospholipids most appropriate to be employed as important pharmaceutical excipients and they have a very wide range of applications in drug delivery systems.The aim of this review is to summarize phospholipids and some of their related applications in drug delivery systems,and highlight the relationship between the properties and applications,and the effect of the species of phospholipids on the efficiency of drug delivery.We refer to some relevant literatures,starting from the structures,main sources and properties of phospholipids to introduce their applications in drug delivery systems.The present article focuses on introducing five types of carriers based on phospholipids,including liposomes,intravenous lipid emulsions,micelles,drug-phospholipids complexes and cochleates.

pH-responsive mesoporous silica nanoparticles employed in controlled drug delivery systems for cancer treatment

In the fight against cancer, controlled drug delivery systems have emerged to enhance the therapeutic efficacy and safety of anti-cancer drugs. Among these systems, mesoporous silica nanoparticles （MSNs） with a functional surface possess obvious advantages and were thus rapidly developed for cancer treatment. Many stimuli-responsive materials, such as nanopartides, polymers, and inorganic materials, have been applied as caps and gatekeepers to control drug release from MSNs. This review presents an overview of the recent progress in the production of pH-responsive MSNs based on the pH gradient between normal tissues and the tumor microenvironment. Four main categories of gatekeepers can respond to acidic conditions. These categories will be described in detail.

Electrospun nanofiber-based drug delivery systems

Electrospinning is a very simple and versatile process by which polymer nanofibers with di-ameters ranging from a few nanometers to sev-eral micrometers can be produced using an electrostatically driven jet of polymer solution or polymer melt. Significant progress has been made in this process throughout the past few years and electrospinning has advanced its ap-plications in many fields, including pharmaceu-tics. Electrospun nanofibers show great prom-ise for developing many types of novel drug delivery systems (DDS) due to their special characteristics and the simple but useful and effective top-down fabricating process. The current state of electrospun nanofiber-based DDS is focused on drug-loaded nanofiber preparation from pharmaceutical and biode-gradable polymers and different types of DDS. However, there are more opportunities to be exploited from the electrospinning process and the corresponding drug-loaded nanofibers for drug delivery. Additionally, some other related challenges and the possible resolutions are outlined in this review.

From oral formulations to drug-eluting implants:using 3D and 4D printing to develop drug delivery systems and personalized medicine

Since the start of the Precision Medicine Initiative by the United States of America in 2015,interest in personalized medicine has grown extensively.In short,personalized medicine is a term that describes medical treatment that is tuned to the individual.One possible way to realize personalized medicine is 3D printing.When using materials that can be tuned upon stimulation,4D printing is established.In recent years,many studies have been exploring a new field that combines 3D and 4D printing with therapeutics.This has resulted in many concepts of pharmaceutical devices and formulations that can be printed and,possibly,tailored to an individual.Moreover,the first 3D printed drug,Spritam®,has already found its way to the clinic.This review gives an overview of various 3D and 4D printing techniques and their applications in the pharmaceutical field as drug delivery systems and personalized medicine.

Ionizable drug delivery systems for efficient and selective gene therapy

Gene therapy has shown great potential to treat various diseases by repairing the abnormal gene function.However,a great challenge in bringing the nucleic acid formulations to the market is the safe and effective delivery to the specific tissues and cells.To be excited,the development of ionizable drug delivery systems(IDDSs)has promoted a great breakthrough as evidenced by the approval of the BNT162b2 vaccine for prevention of coronavirus disease 2019(COVID-19)in 2021.Compared with conventional cationic gene vectors,IDDSs can decrease the toxicity of carriers to cell membranes,and increase cellular uptake and endosomal escape of nucleic acids by their unique pH-responsive structures.Despite the progress,there remain necessary requirements for designing more efficient IDDSs for precise gene therapy.Herein,we systematically classify the IDDSs and summarize the characteristics and advantages of IDDSs in order to explore the underlying design mechanisms.The delivery mechanisms and therapeutic applications of IDDSs are comprehensively reviewed for the delivery of plasmid DNA(pDNA)and four kinds of RNA.In particular,organ selecting considerations and high-throughput screening are highlighted to explore efficiently multifunctional ionizable nanomaterials with superior gene delivery capacity.We anticipate providing references for researchers to rationally design more efficient and accurate targeted gene delivery systems in the future,and indicate ideas for developing next generation gene vectors.

Transdermal drug delivery systems in diabetes management: A review

Diabetes mellitus is a chronic disease in which there is an insufficient production of insulin by the pancreas, or the insulin produced is unable to be utilized effectively by the body. Diabetes affects more than 415 million people globally and is estimated to strike about 642 million people in 2040. The WHO reported that diabetes will become the seventh biggest cause of mortality in 2030. Insulin injection and oral hypoglycemic agents remain the primary treatments in diabetes management. These often present with poor patient compliance. However, over the last decade, transdermal systems in diabetes management have gained increasing attention and emerged as a potential hope in diabetes management owing to the advantages that they offer as compared to invasive injection and oral dosage forms. This review presents the recent advances and developments in transdermal research to achieve better diabetes management. Different technologies and approaches have been explored and applied to the transdermal systems to optimize diabetes management. Studies have shown that these transdermal systems demonstrate higher bioavailability compared to oral administration due to the avoidance of first-pass hepatic metabolism and a sustained drug release pattern. Besides that, transdermal systems have the advantage of reducing dosing frequency as drugs are released at a predetermined rate and control blood glucose level over a prolonged time, contributing to better patient compliance. In summary, the transdermal system is a field worth exploring due to its significant advantages over oral route in administration of antidiabetic drugs and biosensing of blood glucose level to ensure better clinical outcomes in diabetes management.

Mesenchymal stem cells-based drug delivery systems for diabetic foot ulcer:A review

The complication of diabetes,which is known as diabetic foot ulcer(DFU),is a significant concern due to its association with high rates of disability and mortality.It not only severely affects patients’quality of life,but also imposes a substantial burden on the healthcare system.In spite of efforts made in clinical practice,treating DFU remains a challenging task.While mesenchymal stem cell(MSC)therapy has been extensively studied in treating DFU,the current efficacy of DFU healing using this method is still inadequate.However,in recent years,several MSCs-based drug delivery systems have emerged,which have shown to increase the efficacy of MSC therapy,especially in treating DFU.This review summarized the application of diverse MSCs-based drug delivery systems in treating DFU and suggested potential prospects for the future research.

Novel drug delivery systems for inflammatory bowel disease

Inflammatory bowel disease(IBD)is a chronic illness characterized by relapsing inflammation of the intestines.The disorder is stratified according to the severity and is marked by its two main phenotypical representations:Ulcerative colitis and Crohn’s disease.Pathogenesis of the disease is ambiguous and is expected to have interactivity between genetic disposition,environmental factors such as bacterial agents,and dysregulated immune response.Treatment for IBD aims to reduce symptom extent and severity and halt disease progression.The mainstay drugs have been 5-aminosalicylates(5-ASAs),corticosteroids,and immunosuppressive agents.Parenteral,oral and rectal routes are the conventional methods of drug delivery,and among all,oral administration is most widely adopted.However,problems of systematic drug reactions and low specificity in delivering drugs to the inflamed sites have emerged with these regular routes of delivery.Novel drug delivery systems have been introduced to overcome several therapeutic obstacles and for localized drug delivery to target tissues.Enteric-coated microneedle pills,various nano-drug delivery techniques,prodrug systems,lipid-based vesicular systems,hybrid drug delivery systems,and biologic drug delivery systems constitute some of these novel methods.Microneedles are painless,they dislodge their content at the affected site,and their release can be prolonged.Recombinant bacteria such as genetically engineered Lactococcus Lactis and eukaryotic cells,including GM immune cells and red blood cells as nanoparticle carriers,can be plausible delivery methods when evaluating biologic systems.Nano-particle drug delivery systems consisting of various techniques are also employed as nanoparticles can penetrate through inflamed regions and adhere to the thick mucus of the diseased site.Prodrug systems such as 5-ASAs formulations or their derivatives are effective in reducing colonic damage.Liposomes can be modified with both hydrophilic and lipophilic particles and act as lipid-based vesicular systems,while hybrid drug delivery systems containing an internal nanoparticle section for loading drugs are potential routes too.Leukosomes are also considered as possible carrier systems,and results from mouse models have revealed that they control anti-and pro-inflammatory molecules.

Camptothecin-based nanodrug delivery systems

The drug camptothecin has a wide range of antitumor effects in cancers including gastric cancer,rectal and colon cancer,liver cancer,and lung cancer.Camptothecin-based drugs inhibit topoisomerase 1(Topo 1),leading to destruction of DNA,and are currently being used as important chemotherapeutic agents in clinical antitumor treatment.However,the main obstacle associated with cancer therapy is represented by systemic toxicity of conventional anticancer drugs and their low accumulation at the tumor site.In addition,low bioavailability,poor water solubility,and other shortcomings hinder their anticancer activity.Different from traditional pharmaceutical preparations,nanotechnology-dependent nanopharmaceutical preparations have become one of the main strategies for different countries worldwide to overcome drug development problems.In this review,we summarized the current hotspots and discussed a variety of camptothecin-based nanodrugs for cancer therapy.We hope that through this review,more efficient drug delivery systems could be designed with potential applications in clinical cancer therapy.

ROS-responsive drug delivery systems for biomedical applications

In the field of biomedicine, stimuli-responsive drug delivery systems(DDSs) have become increasingly popular due to their site-specific release ability in response to a certain physiological stimulus, which may result in both enhanced treatment outcome and reduced side effects. Reactive oxygen species(ROS) are the unavoidable consequence of cell oxidative metabolism. ROS play a crucial part in regulating biological and physiological processes,whereas excessive intracellular ROS usually lead to the oxidation stress which has implications in several typical diseases such as cancer, inflammation and atherosclerosis. Therefore,ROS-responsive DDSs have elicited widespread popularity for their promising applications in a series of biomedical research because the payload is only released in targeted cells or tissues that overproduce ROS. According to the design of ROS-responsive DDSs, the main release mechanisms of therapeutic agents can be ascribed to ROS-induced carrier solubility change, ROS-induced carrier cleavage or ROS-induced prodrug linker cleavage. This review summarized the latest development and novel design of ROS-responsive DDSs and discussed their design concepts and the applications in the biomedical field.

Formulation of self-nanoemulsifying drug delivery systems containing monoacyl phosphatidylcholine and Kolliphor^(■) RH40 using experimental design

The development of self-nanoemulsifying drug delivery systems(SNEDDS) to enhance the oral bioavailability of lipophilic drugs is usually based on traditional one-factor-at-a-time approaches. These approaches may be inadequate to analyse the effect of each excipient and their potential interactions on the emulsion droplet size formed when dispersing the SNEDDS in an aqueous environment. The current study investigates the emulsion droplet sizes formed from SNEDDS containing different levels of the natural surfactant monoacyl phosphatidylcholine to reduce the concentration of the synthetic surfactant polyoxyl 40 hydrogenated castor oil(Kolliphor ~? RH40). Monoacyl phosphatidylcholine was used in the form of Lipoid S LPC 80(LPC, containing approximately 80% monoacyl phosphatidylcholine, 13% phosphatidylcholine and 4% concomitant components). The investigated SNEDDS comprised of long-chain or medium-chain glycerides(40% to 75%), Kolliphor ~? RH40(5% to 55%), LPC(0 to 40%) and ethanol(0 to 10%). D-optimal design, multiple linear regression, and partial least square regression were used to screen different SNEDDS within the investigated excipient ranges and to analyse the effect of each excipient on the resulting droplet size of the dispersed SNEDDS measured by dynamic light scattering. All investigated formulations formed nano-emulsions with droplet sizes from about 20 to 200 nm. The use of mediumchain glycerides was more likely to result in smaller and more monodisperse droplet sizes compared to the use of long-chain glycerides. Kolliphor~? RH40 exhibited the most significant effect on reducing the emulsion droplet sizes. Increasing LPC concentration increased the emulsion droplet sizes, possibly because of the reduction of Kolliphor~? RH40 concentration. A higher concentration of ethanol resulted in an insignificant reduction of the emulsion droplet size. The study provides different ternary diagrams of SNEDDS containing LPC and Kolliphor ~? RH40 as a reference for formulation developers.

Recent advances in particulate drug delivery systems: Oral, pulmonary, and ophthalmic administrations

Colloidal drug carriers such as liposomes,lipid emulsions,and polymeric nanoparticles have great potential to deliver drugs effectively.Preparation of nano-crystals of API has also received much attention to design dosage forms to complete effective drug delivery.A variety of investigations have been carried out toward the design of an optimal particulate system.

Recent progress of respiratory inhalation drug delivery systems

With the influence of many factors such as the aging of the population,the younger smokers,and the serious air pollution,the incidence of chronic respiratory diseases is increasing year by year.In the treatment of respiratory diseases,clinical intervention is still mainly based on drug control of pulmonary symptoms.However,systemic drugs have disadvantages such as many adverse reactions and severe systemic side effects.In recent years,the research and development of local drug delivery systems for the respiratory tract has brought new changes to the treatment of respiratory diseases.Locally delivered drugs can directly act on the airways and have the characteristics of fast onset,good curative effect and small side effects.It is a simple,efficient and safe treatment method,which has a very significant effect,and has become a hot topic of current research and promotion.This paper briefly reviews the development track and latest research progress of respiratory local drug delivery systems at home and abroad,in order to provide reference for clinical workers in drug selection and application.

Targeted drug delivery systems for pancreatic ductal adenocarcinoma:overcoming tumor microenvironment challenges with CAF-specific nanoparticles

Pancreatic ductal adenocarcinoma(PDAC)stands as a profoundly heterogeneous and aggressive malignancy,manifesting a discouragingly limited response to conventional therapeutic interventions.Within the intricate tapestry of the tumor microenvironment(TME),cancer-associated fibroblasts(CAFs)emerge as pivotal constituents,wielding the capacity to propel the malignant attributes of neoplastic cells while bolstering their deftness in thwarting treatments.The rapid evolution of nanomedicinal technologies ushers in fresh avenues for thera-peutic paradigms meticulously honed to target CAFs.Notably,a recent proposition by Yuan et al.introduces a PDAC treatment strategy metaphorically akin to“shooting fish in a barrel.”By adeptly capitalizing on the spatial distribution of the CAF barricade encircling the tumor,this innovative approach orchestrates a metamorphosis of CAFs,transitioning them from impediments to drug delivery into reservoirs of therapeutic agents.The resultant outcome,an augmentation of chemotherapy and immunotherapy efficacy,attests to the transformative potential of this concept.The study not only bequeaths novel insights and methodologies to surmount barriers in drug delivery for tumor treatment but also holds promise in elevating the precision,efficacy,and safety of tailored therapeutic regimens.Within this discourse,we meticulously evaluate Yuan et al.’s research,scrutinizing its merits and limitations,and cast a forward-looking gaze upon the formulation,validation of efficacy,and clinical translation of nanomedicines targeting CAFs.

A Study on the Multi-Compartment Linear Circulation Pharmacokinetic Model for the Targeting Drug Delivery System

By analyzing the observed phenomena and the data collected in the study, a multi-compartment linear circulation model for targeting drug delivery system was developed and the function formulas of the drug concentration-time in blood and target organ by computing were figured out. The drug concentration-time curve for target organ can be plotted with reference to the data of drug concentration in blood according to the model. The pharmacokinetic parameters of the drug in target organ could also be obtained. The practicability of the model was further checked by the curves of drug concentration-time in blood and target organ(liver) of liver-targeting nanoparticles in animal tests. Based on the liver drug concentration-time curves calculated by the function formula of the drug in target organ, the pharmacokinetic behavior of the drug in target organ(liver) was analyzed by statistical moment, and its pharmacokinetic parameters in liver were obtained. It is suggested that the (relative targeting index( can be used for quantitative evaluation of the targeting drug delivery systems.

5-Fluorouracil-loaded Self-assembled pH-sensitive Nanoparticles as Novel Drug Carrier for Treatment of Malignant Tumors

In order to improve the cancer-targeting and selective activity of antineoplastic agent [5-fluorouracil （5-FU）], a novel pH-responsive drug delivery system [pullulan acetate/sulfonamide （PA/SDM） conjugate] was synthesized by a diafiltration method. Sulfonamide was grafted to the hydrophobicaUy modified pullulan acetate to enhance the pH sensitivity for better cancer-targeting delivery. 5-FU was loaded into the self-assembled nanoparticles by the same method. The drug-loaded self-assembled nanoparticles were successfully obtained and characterized in terms of particle size, morphology and drug loading and release profile at various pHs. The results showed that the mean diameter of the self-assembled particles was approximately 100nm, with uniform size and good spherical morphology. The nanoparticles showed good stability at pH 7.4, which is equal to that of the normal body fluid, but shrank and aggregated below pH 6.8, which is close to the pH with tumors. The loading efficiency and concentration of released 5-FU was monitored at 269 nm on the UVNis spectrophotometer. The release profile was heavily pH-dependent around phvsiological pH, and the release rate was significantly enhanced under pH of 6.8.