Double-Liposome – Based Dual-Drug Delivery System as Vectors for Effective Management of Peptic Ulcer

Progress in the Use of Hydrogels for Antioxidant Delivery in Skin Wounds

The skin is the largest organ of the body, and it acts as a protective barrier against external factors. Chronic wounds affect millions of people worldwide and are associated with significant morbidity and reduced quality of life. One of the main factors involved in delayed wound healing is oxidative injury, which is triggered by the overproduction of reactive oxygen species. Oxidative stress has been implicated in the pathogenesis of chronic wounds, where it is known to impair wound healing by causing damage to cellular components, delaying the inflammatory phase of healing, and inhibiting the formation of new blood vessels. Thereby, the treatment of chronic wounds requires a multidisciplinary approach that addresses the underlying causes of the wound, provides optimal wound care, and promotes wound healing. Among the promising approaches to taking care of chronic wounds, antioxidants are gaining interest since they offer multiple benefits related to skin health. Therefore, in this review, we will highlight the latest advances in the use of natural polymers with antioxidants to generate tissue regeneration microenvironments for skin wound healing.

The 3D Bioprinted Scaffolds for Wound Healing

Skin tissue engineering and regeneration aim at repairing defective skin injuries and progress in wound healing. Until now, even though several developments are made in this field, it is still challenging to face the complexity of the tissue with current methods of fabrication. In this review, short, state-of-the-art on developments made in skin tissue engineering using 3D bioprinting as a new tool are described. The current bioprinting methods and a summary of bioink formulations, parameters, and properties are discussed. Finally, a representative number of examples and advances made in the field together with limitations and future needs are provided.

Potential utility of nano-based treatment approaches to address the risk of Helicobacter pylori

INTRODUCTION

Helicobacter pylori (H. pylori) has occupied a significant place among infectious pathogens and it has been documented as a leading challenge due to its higher resistance to the commonly used drugs, higher adaptability, and lower targeting specificity of the available drugs.

AREAS COVERED

New treatment strategies are urgently needed in order to improve the current advancement in modern medicine. Nanocarriers have gained an advantage of drug encapsulation and high retention time in the stomach with a prolonged drug release rate at the targeted site. This article aims to highlight the recent advances in nanotechnology with special emphasis on metallic, polymeric, lipid, membrane coated, and target-specific nanoparticles (NPs), as well as, natural products for treating H. pylori infection. We discussed a comprehensive approach to understand H. pylori infection and elicits to rethink about the increasing threat posed by H. pylori and its treatment strategies.

EXPERT OPINION

To address these issues, nanotechnology has got huge potential to combat H. pylori infection and has made great progress in the field of biomedicine. Moreover, combinatory studies of natural products and probiotics in conjugation with NPs have proven efficiency against H. pylori infection, with an advantage of lower cytotoxicity, minimal side effects, and stronger antibacterial potential.[Figure: see text].

Phage display-derived antibody fragments against conserved regions of VacA toxin of Helicobacter pylori

Infection with Helicobacter pylori may result in the emergence of gastric adenocarcinoma. Among various toxins assisting pathogenesis of H. pylori, the vacuolating cytotoxin A (VacA) is one of the most potent toxins known as the major cause of the peptic ulcer and gastric adenocarcinoma. To isolate single-chain variable fragments (scFvs) against two conserved regions of VacA, we capitalized on the phage display technology and a solution-phase biopanning (SPB). Characterization of scFvs was carried out by enzyme-linked immunosorbent assay (ELISA), immunoblotting, and surface plasmon resonance (SPR). Bioinformatics analyses were also performed in order to characterize the structural and functional properties of the isolated scFvs and the interaction(s) between the isolated antibodies (Ab)-antigen (Ag). After four rounds of biopanning, the positive colonies detected by scFv ELISA were harvested to extract the plasmids and perform sequencing. Of several colonies, three colonies showed high affinity to the VacA1 and two colonies for the VacA2. Further complementary examinations (e.g., sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), western blot, SPR, and flow cytometry) displayed the high affinity and specificity of the isolated scFvs to the VacA. Docking results revealed the interaction of the complementarity-determining regions (CDRs) with the VacA peptide. In conclusion, for the first time, we report on the isolation of several scFvs against conserved residues of VacA toxin with high affinity and specificity, which may be used as novel diagnostic/therapeutic tool in the H. pylori infection.

Modification of drug delivery to improve antibiotic targeting to the stomach

The obstacles to the successful eradication of Helicobacter pylori infections include the presence of antibiotic-resistant bacteria and therapy requiring multiple drugs with complicated dosing schedules. Other obstacles include bacterial residence in an environment where high antibiotic concentrations are difficult to achieve. Biofilm production by the bacteria is an additional challenge to the effective treatment of this infection. Conventional oral formulations used in the treatment of this infection have a short gastric residence time, thus limiting the duration of exposure of drug to the bacteria. This review summarizes the current research in the development of gastroretentive formulations and the prospective future applications of this approach in the targeted delivery of drugs such as antibiotics to the stomach.

Recent advances in liposome surface modification for oral drug delivery

Oral delivery via the gastrointestinal (GI) tract is the dominant route for drug administration. Orally delivered liposomal carriers can enhance drug solubility and protect the encapsulated theraputic agents from the extreme conditions found in the GI tract. Liposomes, with their fluid lipid bilayer membrane and their nanoscale size, can significantly improve oral absorption. Unfortunately, the clinical applications of conventional liposomes have been hindered due to their poor stability and availability under the harsh conditions typically presented in the GI tract. To overcome this problem, the surface modification of liposomes has been investigated. Although liposome surface modification has been extensively studied for oral drug delivery, no review exists so far that adequately covers this topic. The purpose of this paper is to summarize and critically analyze emerging trends in liposome surface modification for oral drug delivery.

Dual release of a hydrophilic and a hydrophobic osteogenic factor from a single liposome

Dual release of growth/differentiation factors from liposomes induced osteogenic differentiation of mesenchymal stem cells.

Nanomedicines in gastroenterology and hepatology

Nanoscale systems are currently under investigation for multiple different diagnostic and therapeutic applications. These systems can be used to identify pathologically changed tissues or to selectively deliver drugs to these sites; both applications have an extremely high potential to ameliorate therapeutic outcomes for patients. Tissues as well as single cells can be targeted because of the small size of these systems, which enables enhanced diagnosis and increased specificity of therapy. Drug loads can be delivered directly to the site of action, which can result in a reduction in incidence and severity of adverse systemic effects. Several nano-based platform technologies are currently under investigation for use in therapeutic approaches, mainly for anti-inflammatory and anti-cancer therapies. Although many nanoscale systems show promising therapeutic outcomes in preclinical studies, only a limited number are ready for clinical use. This Review will discuss the diverse nanomaterials currently available and the first specific uses for select gastroenterological and hepatological pathologies. The discussion of diagnostic and therapeutic applications will consider realities of market introduction of these sometimes very complex systems in light of remaining regulatory challenges and hurdles for industrial production.

Eradication of Helicobacter pylori: Past, present and future

Helicobacter pylori is the major cause of chronic gastritis and peptic ulcers. Since the classification as a group 1 carcinogenic by International Agency for Research on Cancer, the importance of the complete H. pylori eradication has obtained a novel meaning. Hence, several studies have been made in order to deepen the knowledge in therapy strategies. However, the current therapy presents unsatisfactory eradication rates due to the lack of therapeutic compliance, antibiotic resistance, the degradation of antibiotics at gastric pH and their insufficient residence time in the stomach. Novel approaches have been made in order to overcome these limitations. The purpose of this review is to provide an overview about the current therapy and its limitations, while highlighting the possibility of using micro- and nanotechnology to develop gastric drug delivery systems, overcoming these difficulties in the future.

Application of liposomes in drug development--focus on gastroenterological targets

Over the past decade, liposomes became a focal point in developing drug delivery systems. New liposomes, with novel lipid molecules or conjugates, and new formulations opened possibilities for safely and efficiently treating many diseases including cancers. New types of liposomes can prolong circulation time or specifically deliver drugs to therapeutic targets. This article concentrates on current developments in liposome based drug delivery systems for treating diseases of the gastrointestinal tract. We will review different types and uses of liposomes in the development of therapeutics for gastrointestinal diseases including inflammatory bowel diseases and colorectal cancer.