Current Drug Delivery - Volume 19, Issue 10, 2022

The direct delivery of therapeutic molecules is generally inefficient and has several problems. Hence, nanomedicines with targeted and controlled delivery applications have been an exciting field of research for the past decade. In this regard, the adjustable properties of inorganic nanoparticles like particle size distribution, ability to change the targeting ligand to have a higher affinity towards the pathologic cell, and controlled delivery properties have made them indispensable for targeted drug delivery applications. Changing the ligand on the surface of the inorganic nanoparticle can direct different therapeutic molecules to different organs like the liver, spleen, kidney, bone, and even brain. However, while the other targeted nanomedicines are well-reported, the targeting of therapeutics to bone marrow cells is sparse in the literature. Hence, the administration of therapeutics for bone-related disorders, like bone metastases, leads to several problems, such as severe systemic toxicity and suboptimal efficacy. In this direction, we have shown our successful effort to functionalise a model inorganic nanoparticle (Fe2O3) by glutamate ligand which is reported to have a high affinity towards the NMDA receptors of the bone cells. We have performed spectroscopic studies to characterize the nano-hybrid. We have shown that the cargo or the Fe2O3 nanoparticle possesses the ability to generate photo-induced reactive oxygen species (ROS), thereby leading to a therapeutic opportunity for bone metastases. In addition, the nanoparticle also possesses the ability to generate enhanced ROS on X-ray irradiation, which may provide a new strategy for bone metastases and cancer therapy. Also, this paper reviews the advancement in the drug delivery applications of inorganic nanoparticles and highlights the crosstalk between the inorganic nanoparticles with the conjugated targeting ligand for efficient delivery applications.

Background: Lipid nanocarriers have great potential for the encapsulation and delivery of numerous bioactive compounds. They have demonstrated significant benefits over traditional disease management and conventional therapy. The benefits associated with the particular properties of lipid nanocarriers include site-specific drug deposition, improved pharmacokinetics and pharmacodynamics, enhanced internalization and intracellular transport, biodegradability, and decreased biodistribution. These properties result in the alleviation of the harmful consequences of conventional treatment protocols. Materials & Methods: The administration of various bioactive molecules has been extensively investigated using nanostructured lipid carriers. In this article, theranostic applications of novel formulations of lipid nanocarriers combined or complexed with quantum dots, certain polymers, such as chitosan, and metallic nanoparticles (particularly gold) are reviewed. These formulations have demonstrated better controlled release features, improved drug loading capability, as well as a lower burst release rate. As a recent innovation in drug delivery, tocosomes and their unique advantages are also explained in the final section of this review. Results and Conclusion: Theranostic medicine requires nanocarriers with improved target-specific accumulation and bio-distribution. To this end, lipid-based nanocarrier systems and tocosomes combined with unique properties of quantum dots, biocompatible polymers, and metallic nanoparticles seem to be ideal candidates to be considered for safe and efficient drug delivery.

Cancer is one of the leading causes of mortality worldwide. Although chemotherapeutic agents have been effectively designed to increase the survival rates of some patients, the designed chemotherapeutic agents necessarily deliver toxic chemotherapeutic drugs to healthy tissues, resulting in serious side effects. Cancer cells can often acquire drug resistance after repeatedly administering current chemotherapeutic agents, restricting their efficacy. Given such obstacles, investigators have attempted to distribute chemotherapeutic agents using targeted drug delivery systems (DDSs), especially nanotechnology-based DDSs. The lipid-based nanoparticles (LBNPs) are a large and complex class of substances utilized to manage various diseases, especially cancers. Liposomes seem to be the most frequently employed LBNPs, owing to their high biocompatibility, bioactivity, stability, and flexibility. Solid lipid NPs and non-structured lipid carriers have lately received a lot of interest. In addition, several reports focused on novel therapies via LBNPs to manage various forms of cancer. In the present research, the latest improvements in applying LBNPs have been shown to deliver different therapeutic agents to cancerous cells and be a quite successful candidate in cancer therapy.

Disorders of the brain constitute the most debilitating situation globally with increased mortality rates every year, while brain physiology and cumbersome drug development processes exacerbate this. Although blood-brain barrier (BBB) and its components are important for brain protection, their complexity creates major obstacles for brain drug delivery, and the BBB is the primary cause of treatment failure, leading to disease progression. Therefore, developing an ideal platform that can predict the behavior of a drug delivery system in the brain at the early development phase is extremely crucial. In this direction, in the last two decades, numerous in vitro BBB models have been developed and investigated by researchers to understand the barrier properties and how closely the in vitro models mimic in vivo BBB. In-vitro BBB models mainly involve the culture of endothelial cells or their coculture with other perivascular cells either in two or three-dimensional platforms. In this article, we have briefly summarized the fundamentals of BBB and outlined different types of in vitro BBB models with their pros and cons. Based on the available reports, no model seems to be robust that can truly mimic the entire properties of the in vivo BBB microvasculature. However, human stem cells, coculture and threedimensional models have been found to mimic the complexity of the barrier integrity not completely but more precisely than other in vitro models. More studies aiming towards combining these models together would be needed to develop an ideal in vitro model that can overcome the existing limitations and unravel the mysterious BBB vasculature.

Introduction: Chronotherapy is the administration of medication according to the biological rhythm to maximize pharmacological effects and minimize side effects. The objective of the current investigation is to prepare delayed-release beads (DRBs) containing montelukast sodium (MKS) for chronotherapy of asthma. Methods: Delayed-release beads of alginate were prepared using a simple method, i.e., ionotropic gelation. The effect of cross-linking agents (zinc or calcium ions) and the concentration of chitosan on the properties of the beads were investigated. The prepared beads were coated by a polymer having pHindependent solubility, i.e., Eudragit RSPO and Eudragit RLPO in different ratios to achieve the desired lag time of 4-5 h. Beads were evaluated for surface morphology, practical yield, encapsulation efficiency, XRD, and in vitro release study. The pharmacokinetic study was carried out on New Zealand white male rabbits. Results: No major differences in the drug release profile were observed between Ca++ and Zn++ crosslinked beads. However, a slight slow release was seen in the case of chitosan-reinforced beads. MKS released from cross-linked alginate beads was slightly altered with sodium alginate concentration, crosslinking time, and talc. At a higher alginate concentration, slow drug release was observed, whereas the addition of talc to alginate increased the release rate. The in vitro release study showed that the optimal formulation of DRBs has a lag time of 4.5 h, and the release at 6 h was found to be 74.9%. In vivo pharmacokinetic study of the beads showed Tmax at 7 h with an initial lag time of 4 h. Conclusion: When dosed at sleep time, the prepared cross-linked beads may deliver montelukast sodium required to relieve early morning symptoms in asthmatic patients.

Background: The main limitations of the therapeutic effectiveness of tizanidine hydrochloride (TNZ) are its low bioavailability due to its tendency to undergo first-pass metabolism and short biological half-life. These factors make it an ideal candidate for formulating orally disintegrating films. Objective: The present study was aimed to prepare nanoparticles of tizanidine hydrochloride using biodegradable polymers and loading them on orodispersible films to obtain a sustained release dissolution profile with improved permeability and further study the cytotoxicity on A549 lung carcinoma cells, MCF7 breast cancer cells, and HOP 92 non-small lung adenocarcinoma cells. Methods: The fast-dissolving film of TNZ HCl was prepared by the solvent-casting method and characterized using scanning electron microscopy, FTIR, and XRD, and evaluated for critical quality attributes for this type of dosage form such as disintegration time, tensile strength, drug content, dissolution, and ex vivo permeability. In vitro cytotoxicity studies were also conducted on cancer cell lines to confirm the cytotoxic effect. Results: The polymeric matrix containing the drug provided a rapid disintegration time varying between 7±2 and 30±2 seconds, adequate tensile strength between 1.4 and 11.25 N/mm2, and improved permeability through porcine buccal mucosa when compared to the reference product. Conclusion: A study of the cytotoxic effect on the MCF-7 breast cancer cells and A549 lung carcinoma cells revealed that tizanidine hydrochloride nanoparticles at 2.3 mg/film exhibited an IC50 value of 65.1 % cytotoxicity on MCF-7, approximately 100% on HOP92, and 83.5 % on A549 lung carcinoma cells, thus paving the way for a new paradigm of research for a cytotoxic study on MCF-7, HOP92, and A549 cell lines using the subject drug model prepared as oral films or biodegradable nanoparticles in oral films for site-specific targeting.

Objective: Lung cancer is one of the main causes of mortality globally. This research paper aims a the development of inhaled nanotechnology for lung cancer to deliver an atorvastatin calcium compound, for lung cancer, capable of reaching the tumor site directly via inhalation. Methods: Atorvastatin calcium micellar nanoparticles (ATO-NPs) encapsulated with Pluronic F-127 and polyvinyl alcohol (PVA) were manufactured utilizing the solvent and anti-solvent precipitation technique. The physicochemical features of the formulation were evaluated in terms of their physicochemical characteristics using Fourier transform infrared spectroscopy, differential scanning calorimetry, and dynamic light scattering. Additionally, the Andersen Cascade impactor was used at 15 L/minutes to assist in the aerosols performances of the formulation. The ATO-NPs formula's cell viability was tested in vitro using the A549 non-small cell lung cancer cell type. Results: Transmission electron microscopy was utilized to determine the ATO-NPs particle morphology, demonstrating a spherical shape with a smooth surface. The fine particle fraction of the aerosol produced was 62.70 ± 1.18%. This finding suggests that atorvastatin micellar nanoparticles are suitable for medication administration by inhalation with a wide particle size dispersion. Moreover, it was found in vitro that concentrations of up to 21 μg/mL of the atorvastatin nanoparticles were safe and non-toxic in the cell model. Conclusion: This study found that atorvastatin micellar nanoparticles for inhalation could potentially be used for lung cancer treatment.

Background and Objectives: DNA-based therapeutic vaccines have been proposed as a promising strategy for the treatment of established HIV infections. However, these vaccines are often associated with certain shortcomings, such as poor immunogenicity and low transfection efficiency. In this study, we investigated the ability of LL-37 to deliver a potential immunogenic fusion construct comprising HIV-1 nef and vpr genes into a mammalian cell line. Methods: First, the pEGFP-N1 eukaryotic expression vector harboring the HIV-1 nef-vpr fusion was produced free of endotoxin on a large scale. Then, DNA/LL-37 complexes were prepared by coincubation of pEGFP-nef-vpr with LL-37 for 45 minutes at different nitrogen to phosphate (N/P) ratios. The formation of DNA/peptide complexes was investigated by gel retardation assay. Next, the stability and morphological characteristics of the nanoparticles were evaluated. The toxicity of LL-37 and the nanoparticles in HEK-293T cells were assessed by MTT assay. The transfection efficiency of the DNA/LL-37 complexes was studied by fluorescence microscopy, flow cytometry, and western blot analysis. Results: LL-37 formed stable complexes with pEGFP-nef-vpr (diameter of 150-200 nm) while providing good protection against nucleolytic and proteolytic degradation. The peptide significantly affected cell viability even at low concentrations. However, the LL-37/DNA complexes had no significant cytotoxic effect. Treatment of cells with pEGFP-N1/LL-37 and pEGFP-nef-vpr/LL-37 resulted in transfection of 36.32% ± 1.13 and 25.55% ± 2.07 of cells, respectively. Conclusion: Given these findings and the important immunomodulatory and antiviral activities of LL- 37, the use of this peptide can be further exploited in the development of novel gene delivery strategies and vaccine design.

Objective: This study evaluated drug delivery systems based on Pectin (P) and Zein (Z) hydrogel microspheres. Piroxicam (Px) loaded P/Z hydrogel microspheres (P/Z HM) were developed, and their extended-release pharmacokinetic properties were evaluated. Methods: Experiments were executed under three different conditions: in vitro, ex vivo, and in vivo. Then, the in vitro-in vivo correlations (IVIVC) and ex vivo-in vivo correlations (EVIVC) were examined. Results: Analysis of drug release mechanisms were evaluated by fitting the in vitro data into the Ritger- Peppas equation, showing the contribution of both polymers’ relaxation and drug diffusion from the hydrogel microspheres. The fraction absorbed in vivo was determined by the deconvolution of plasma concentration data using the Loo-Riegelman method. After oral single-dose administration of the two formulations, their basic independent model parameters were calculated. Conclusion: P/Z HM had different drug release behaviors in in vitro and in vivo conditions. However, the ex vivo and in vivo characteristics were similar (R² = 0.99). It seemed reasonable to use the ex vivo method to predict the in vivo drug absorption behavior during the polymeric drug delivery system developmental studies. The P/Z HM formulation maintained the drug dose at the colon site for a long duration and could be applied for delivery of active pharmaceutical and food ingredients to the colon site.

Background: Chronic wound healing is a major challenge for the health care system around the globe. The current study was conducted to develop and characterize chemically cross-linked polyethylene glycol-co-poly (AMPS) hydrogel membranes to enhance the wound healing efficiency of antibiotic mupirocin (MP). Methods: Free radical polymerization technique was used to develop hydrogel membranes. In an aqueous medium, polymer PEG-4000 was cross-linked with the monomer 2-acrylamido-2-methylpropane sulfonic acid (AMPS) in the presence of initiators ammonium peroxide sulfate (APS) and sodium hydrogen sulfite (SHS). N, N-Methylene-bis-acrylamide (MBA) was used as a cross-linker in preparing hydrogel membranes. Developed membranes were spherical, transparent, and had elasticity. FTIR, TGA/DSC, and SEM were used to characterize the polymeric system. Swelling behavior, drug loading, and release pattern at pH of 5.5 and 7.4, irritation study, ex vivo drug permeation, and deposition study were also evaluated. Results: Formed membranes were spherical, transparent, and had elasticity. The formation of a stable polymeric network was confirmed by structural and thermal analysis. Evaluation of the drug permeability in the skin showed good permeation and retention capabilities. No irritancy to the skin was observed. Conclusion: Based on the results obtained, the present study concluded that the formulated stable network might be an ideal network for the delivery of mupirocin in skin infections.