Magnetically Guided Rat Erythrocytes Bearing Isoniazid: Preparation, Characterization, and Evaluation

Strategies and progresses for enhancing targeted antibiotic delivery

Antibiotic resistance is a global health issue and a potential risk for society. Antibiotics administered through conventional formulations are devoid of targeting effect and often spread to various undesired body sites, leading to sub-lethal concentrations at the site of action and thus resulting in emergence of resistance, as well as side effects. Moreover, we have a very slim antibiotic pipeline. Drug-delivery systems have been designed to control the rate, time, and site of drug release, and innovative approaches for antibiotic delivery provide a glint of hope for addressing these issues. This review elaborates different delivery strategies and approaches employed to overcome the limitations of conventional antibiotic therapy. These include antibiotic conjugates, prodrugs, and nanocarriers for local and targeted antibiotic release. In addition, a wide range of stimuli-responsive nanocarriers and biological carriers for targeted antibiotic delivery are discussed. The potential advantages and limitations of targeted antibiotic delivery strategies are described along with possible solutions to avoid these limitations. A number of antibiotics successfully delivered through these approaches with attained outcomes and potentials are reviewed.

Blood cell-based drug delivery systems: a biomimetic platform for antibacterial therapy

With the rapid increase in multidrug-resistance against antibiotics, higher doses of antibiotics or more effective antibiotics are needed to treat diseases, which ultimately leads to a decrease in the body's immunity and seriously threatens human health worldwide. The efficiency of antibiotics has been a large challenge for years. To overcome this problem, many carriers are utilized for anti-bacteria, attempting to optimize the delivery of such drugs and transport them safely and directly to the site of disease. Blood cell-based drug delivery systems present several advantages as compared to polymeric delivery system. These blood cells including red blood cells (RBCs), leukocytes, platelets. The blood cells and their membranes can both be used as drug carriers to deliver antibacterial drugs. In addition, blood cells can overcome many physiological/pathological obstacles faced by nanoparticles in vivo and effectively deliver drugs to the site of the disease. In this paper, we review studies on blood cell-based delivery systems used in antibacterial therapy, and analyze different roles in antibacterial therapy, which provide basis for further study in this field.

Recent Progress in Red Blood Cells-Derived Particles as Novel Bioinspired Drug Delivery Systems: Challenges and Strategies for Clinical Translation

Red Blood Cells (RBCs)-derived particles are an emerging group of novel drug delivery systems. The natural attributes of RBCs make them potential candidates for use as a drug carrier or nanoparticle camouflaging material as they are innately biocompatible. RBCs have been studied for multiple decades in drug delivery applications but their evolution in the clinical arena are considerably slower. They have been garnering attention for the unique capability of conserving their membrane proteins post fabrication that help them to stay non-immunogenic in the biological environment prolonging their circulation time and improving therapeutic efficiency. In this review, we discuss about the synthesis, significance, and various biomedical applications of the above-mentioned classes of engineered RBCs. This article is focused on the current state of clinical translation and the analysis of the hindrances associated with the transition from lab to clinic applications.

Macromolecular Conjugate and Biological Carrier Approaches for the Targeted Delivery of Antibiotics

For the past few decades, the rapid rise of antibiotic multidrug-resistance has presented a palpable threat to human health worldwide. Meanwhile, the number of novel antibiotics released to the market has been steadily declining. Therefore, it is imperative that we utilize innovative approaches for the development of antimicrobial therapies. This article will explore alternative strategies, namely drug conjugates and biological carriers for the targeted delivery of antibiotics, which are often eclipsed by their nanomedicine-based counterparts. A variety of macromolecules have been investigated as conjugate carriers, but only those most widely studied in the field of infectious diseases (e.g., proteins, peptides, antibodies) will be discussed in detail. For the latter group, blood cells, especially erythrocytes, have been successfully tested as homing carriers of antimicrobial agents. Bacteriophages have also been studied as a candidate for similar functions. Once these alternative strategies receive the amount of research interest and resources that would more accurately reflect their latent applicability, they will inevitably prove valuable in the perennial fight against antibiotic resistance.

Resealed Erythrocytes as Drug Carriers and Its Therapeutic Applications

In this pharma innovative world, there are more than 30 drug delivery systems. Today's due to lacking the target specificity, the present scenario about drug delivery is emphasizing towards targeted drug delivery systems. Erythrocytes are the most common type of blood cells travel thousands of miles from wide to narrow pathways to deliver oxygen, drugs and nutrient during their lifetime. Red blood cells have strong and targeted potential carrier capabilities for varieties of drugs. Drug-loaded carrier erythrocytes or resealed erythrocytes are promising for various passive and active targeting. Resealed erythrocyte have advantage over several drug carrier models like biocompatibility, biodegradability without toxic products, inert intracellular environment, entrapping potential for a variety of chemicals, protection of the organism against toxic effects of the drug, able to circulate throughout the body, ideal zero-order drug-release kinetics, no undesired immune response against encapsulated drug etc. Resealed erythrocytes are rapidly taken up by macrophages of the Reticuloendothelial System (RES) of the liver, lung, and spleen of the body and hence drugs also. Resealed erythrocytes method of drugs delivery is secure and effective for drugs targeting specially for a longer period of time. This chapter will explain the different method of drug loading for resealed erythrocytes, their characterization, and applications in various therapies and associated health benefits.

Biochemically altered human erythrocytes as a carrier for targeted delivery of primaquine: an in vitro study

The aim of this study was to investigate human erythrocytes as a carrier for targeted drug delivery of primaquine (PQ). The process of PQ loading in human erythrocytes, as well as the effect of PQ loading on the oxidative status of erythrocytes, was also studied. At PQ concentrations of 2, 4, 6, and 8 mg/mL and an incubation time of 2 h, the ratios of the concentrations of PQ entrapped in erythrocytes to that in the incubation medium were 0.515, 0.688, 0.697 and 0.788, respectively. The maximal decline of erythrocyte reduced glutathione content was observed at 8 mg/mL of PQ compared with native erythrocytes p < 0.001. In contrast, malondialdehyde and protein carbonyl were significantly increased in cells loaded with PQ (p < 0.001). Furthermore, osmotic fragility of PQ carrier erythrocytes was increased in comparison with unloaded cells. Electron microscopy revealed spherocyte formation with PQ carrier erythrocytes. PQ-loaded cells showed sustained drug release over a 48 h period. Erythrocytes were loaded with PQ successfully, but there were some biochemical as well as physiological changes that resulted from the effect of PQ on the oxidative status of drug-loaded erythrocytes. These changes may result in favorable targeting of PQ-loaded cells to reticulo-endothelial organs. The relative impact of these changes remains to be explored in ongoing animal studies.

Magnetic targeting for site-specific drug delivery: applications and clinical potential

BACKGROUND

Magnetic vehicles are very attractive for delivery of therapeutic agents as they can be targeted to specific locations in the body through the application of a magnetic field gradient. The magnetic localization of a therapeutic agent results in the concentration of the therapy at the target site consequently reducing or eliminating the systemic drug side effects.

OBJECTIVE

The aim of this review is to provide an update on the progress made in the development of the magnetic targeting technique addressing characteristics of the magnetic carriers and limitations of the current targeting magnet systems.

METHODS

This review discusses fundamental requirements for the optimal formulation of the magnetic carrier, current applications and potentially new approaches for the magnetically mediated, site-specific localization of therapeutic agents, including drugs, genes and cells.

RESULTS/CONCLUSION

More efficient targeting magnetic systems in combination with prolonged circulation lifespan and carriers' surface recognition properties will improve the targeting efficiency of magnetic nanocarriers and enhance therapeutic agent availability at the molecular site of agent action. The main future magnetic targeting applications were categorized emphasizing the most promising directions and possible strategies for improving the magnetic targeting technique.

Preparation and Validation of Carrier Human Erythrocytes Loaded by Bovine Serum Albumin as a Model Antigen/Protein

Erythrocytes as the most readily available and abundant cells within the body have been studied extensively for their potential application as drug delivery carries. In this study, human erythrocytes were loaded by bovine serum albumin (BSA) as a model antigen/protein using hypotonic preswelling method for targeted delivery of this antigen-to antigen-presenting cells. The average loaded amount, efficiency of entrapment, and cell recovery upon loading procedure were 1979.25 +/- 9.4 microg, 30.06 +/- 0.20%, and 87.53 +/- 0.66%, respectively. The total BSA recovery upon loading procedure was 97.20 +/- 4.90%. The apparent mechanism of entrapment was simple concentration-based gradient in/out the cells with some minor limiting factors against protein entry into the cells. We have shown that the intra- and intersubject variations of the method were interestingly low (i.e., less than 5% in all cases).

Preparation and in vitro evaluation of carrier erythrocytes for RES-targeted delivery of interferon-alpha 2b

Carrier erythrocytes is one of the most promising systemic drug delivery systems investigated in recent decades. In this study, human erythrocytes have been loaded with interferon-alpha 2b (IFN) with the aim to benefit the reticuloendothelial system (RES) targeting potential of the carrier cells. Hypotonic preswelling method was used for drug loading in erythrocytes and the entire loading procedure was evaluated and validated. The loaded amount, entrapment efficiency and cell recovery of the loading procedure were 2906.33+/-588.35IU/0.1ml, 14.53+/-2.94%, and 83.61+/-0.49%, respectively, all being practically feasible. The carrier erythrocytes were characterized in vitro in terms of their drug release kinetics, hematological indices, particle size distribution, SEM analysis, and osmotic and turbulence fragility. IFN release from carrier cells was a relatively rapid process in comparison to the cell lysis kinetics, which is unusual considering the whole body of data published on this delivery system and other protein drugs, so far. All the tested in vitro characteristics showed significant, sometimes notable changes upon drug loading procedure, both with and without the drug.

Preparation and in vitro characterization of carrier erythrocytes for vaccine delivery

Erythrocytes as the most readily available and abundant cells within the body, have been studied extensively for their potential application as drug delivery carriers. In this study, human erythrocytes have been loaded by bovine serum albumin (BSA) as a model antigen/protein using hypotonic preswelling method for targeted delivery of this antigen to antigen-presenting cells (APCs). A series of in vitro tests have been carried out to characterize the carrier cells in vitro, including loading parameters, BSA and hemoglobin release kinetics, hematological indices, particle size distribution, SEM analysis, osmotic and turbulence fragility, and osmotic competency. BSA was loaded in erythrocytes with a loaded amount of 1.98+/-0.009mg with antigen release from carrier cells showing a zero-order kinetic consistent to that of the cell lysis. The apparent cell sizes, measured using laser scattering, were not significantly different from normal erythrocytes, but the real sizes, measured using SEM, and surface topologies were quite different between loaded and unloaded cells. The BSA-loaded cells were remarkably more fragile and less deformable compared to the normal cells. Totally, BSA-loaded erythrocytes seem to be a promising delivery system for reticuloendothelial system (RES) targeting of the antigens.

Applications of carrier erythrocytes in delivery of biopharmaceuticals

Carrier erythrocytes, resealed erythrocytes loaded by a drug or other therapeutic agents, have been exploited extensively in recent years for both temporally and spatially controlled delivery of a wide variety of drugs and other bioactive agents owing to their remarkable degree of biocompatibility, biodegradability and a series of other potential advantages. Biopharmaceuticals, therapeutically significant peptides and proteins, nucleic acid-based biologicals, antigens and vaccines, are among the recently focused pharmaceuticals for being delivered using carrier erythrocytes. In this article, the potential applications of erythrocytes in drug delivery have been reviewed with a particular stress on the studies and laboratory experiences on successful erythrocyte loading and characterization of the different classes of biopharmaceuticals.