Recent advances in liposome-based targeted cancer therapy.

Nano-drug delivery systems have opened new pathways for tumor treatment by overcoming some of the limitations of conventional drugs, such as physiological degradation, short half-life, and rapid release. Liposomes are promising nanocarrier systems due to their biocompatibility, low toxicity, and high inclusivity, as well as their enhanced drug bioavailability. Various strategies for active targeting of liposomal formulations have been investigated to achieve the highest drug efficacy. This review aims to summarize current developments in novel liposomal formulations, particularly ligand-targeted liposomes (such as folate, transferrin, hyaluronic acid, antibodies, aptamer, and peptide, etc.) used for the therapy of various cancers and provide an insight on the challenges and future of liposomes for scientists and pharmaceutical companies.

Cell culture and pharmacokinetic evaluation of a solid dosage formulation containing a water-insoluble orphan drug manufactured by FDM-3DP technology.

The in-vitro cytotoxicity, in-vitro permeability and in-vivo pharmacokinetics of a BCS Class-II drug - rufinamide - in a 3DP tablet formulation were evaluated. The cytotoxicity of the 3DP tablet formulation was evaluated with an MTT test; in-vitro permeability was evaluated with a Caco-2 cell culture study; and in-vivo pharmacokinetics were evaluated in Wistar albino male rats. The pharmacokinetic studies were performed following a two-sequence and single-period design approach. The highest Caco-2 permeability was obtained with the 3DP tablet formulation; and the highest cell viability was achieved with the 3DP tablet in both the Hep G2 and Caco-2 cell lines. In the in-vivo pharmacokinetic study, AUC and Cmax values were higher in the 3DP tablet formulation than in the Inovelon® film tablet at a 40 mg/kg dose. Thanks to the increased solubility of the active substance, higher in-vitro permeability and in-vivo absorption were achieved with the 3DP tablet formulation, and with lower cytotoxicity. Based on these promising findings, the 3DP tablet formulation can be considered an effective lower-dose treatment than commercial preparations.

Do Thickening Agents Used in Dysphagia Diet Affect Drug Bioavailability?

Swallowing oral solid dosage forms is challenging in patients with dysphagia who are at risk of aspiration or choking. The most common method to facilitate drug administration in dysphagia patients is to mix the powdered drug with a small amount of thickened water, however little is known about the effects of this method on in vivo bioavailability of drugs. This study aimed to evaluate the impact of thickened liquids on dissolution rate and bioavailability of levetiracetam as a model drug. Powdered commercial tablets of levetiracetam, carbamazepine, atenolol and cefixime were mixed with water thickened with two commercial thickeners, modified maize starch (MS) and xanthan gam (XG), at three thickness levels: nectar, honey and pudding in test groups, and mixed with only water in the control group. At the first stage, the effects of thickened water on in vitro drug release of 4 drugs (levetiracetam, carbamazepine, atenolol and cefixime) were tested by using dialysis membrane method. Addition of both thickeners significantly reduced the release of three drugs compared to the control group, except carbamazepine. Levetiracetam which had the highest solubility was chosen as the model drug for in vivo experiments. In the second stage, New Zealand albino female rabbits (n=24) were divided into two groups as: control group (water+drug, n=6) and test group (thickened water+drug, n=18). Powdered levetiracetam tablets were mixed with water thickened with XG (n=9, 1.2%, 2.4%, 3.6%) and MS (n=9, 4%, 6%, 8%) at three thickness levels and administered to the rabbits by intragastric gavage. Blood samples were collected at 9 time points following administration. After two-weeks of wash-out, test groups were crossed over and sample collection was repeated. Blood samples were analysed using liquid chromatography with tandem mass spectrometry (LC-MS/MS). An in vitro-in vivo correlation (IVIVC) model was developed using in vitro drug dissolution (%) and in vivo plasma concentrations of levetiracetam for control group and test groups. The peak plasma concentration (Cmax) was lower and time to reach Cmax (tmax) was relatively higher in test groups compared to control group. The lowest Cmax was detected at the highest thickness level, however, the differences between groups were not statistically significant (p=0.117 and p=0.495 for Cmax and tmax, respectively). No significant difference in total amount of levetiracetam absorbed (AUC) was found between groups (p=0.215 and p=0.183 for AUCinfinity and AUClast, respectively). The comparisons according to the type of thickener also revealed that pharmacokinetic parameters did not significantly differ between groups, except for a significantly lower Cmax when drug was mixed with MS-thickened water at nectar consistency (1.2%) compared to drug mixed with XG (4%) at the same thickness level (p=0.038). A good correlation was observed between in vitro and in vivo data, which was characterized by higher r2 values as the concentration of the thickening agents was increased, but not for all thickness levels studied, indicating an inability of this in vitro model to fully predict the in vivo response. These results suggest that regardless of the thickness level, the administration of levetiracetam with two commercial thickening agents commonly used in dysphagia for safe swallowing, do not affect the pharmacokinetic efficiency and thus, the bioavailability of the drug.

A stability indicating RP-HPLC method for determination of the COVID-19 drug molnupiravir applied using nanoformulations in permeability studies.

Antiviral drugs have gained much more attention in recent years due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and many drug candidates are currently under investigation in order to end pandemic. Molnupiravir, a prodrug of the synthetic nucleoside derivative N4-hydroxycytidine, is one of the promising candidates for SARS-CoV-2 treatment. In this study, a RP-HPLC method was developed for the determination of Molnupiravir and applied for in vitro permeability studies of self-emulsifying drug delivery system (SEDDS) formulations using Caco-2 cell line. Discovery® HS C18 Column (75 ×4.6 mm, 3 µm) was used at 30 °C. Isocratic elution was performed with ACN:water (20:80 v/v) mixture. The flow rate was 0.5 mL/min and UV detection was at 240 nm. Molnupiravir eluted within 5 min. Molnupiravir was exposed to thermal, photolytic, hydrolytic, and oxidative stress conditions. Peak homogeneity data of Molnupiravir in the stressed samples peak obtained using photodiode array detector, in the stressed sample chromatograms, demonstrated the specificity of the method for their estimation in presence of degradants. The developed method was validated according to the International Council for Harmonisation (ICH) guidelines and found to be linear within the range 0.1-60.0 µg/mL. The method was simple, rapid, selective, sensitive, accurate, precise, robust and rugged. Thus, it was applied successfully for permeability quantitation of Molnupiravir in nanoformulations. The apparent permeability of Molnupiravir in SEDDS formulations, which have droplet size under 350 nm, was calculated as 3.20 ± 0.44 × 10-6 cm/s.

The role of peptide-based therapeutics in oncotherapy.

Cancer is the second leading cause of death worldwide, and the search for specialised therapy options has been a challenge for decades. The emergence of active targeted therapies provides the opportunity to treat cancerous tissues without harming healthy ones due to peculiar physiological changes. Herein, peptides and peptide analogs have been gaining a lot of attention over the last decade, especially for the on-site delivery of therapeutics to target tissues in order to achieve efficient and reliable cancer treatment. Combining peptides with highly efficient drug delivery platforms could potentially eliminate off-target adverse effects encountered during active targeting of conventional chemotherapeutics. Small size, ease of production and characterisation, low immunogenicity and satisfactory binding affinity of peptides offer some advantages over other complex targeting moiety, no wonder the market of peptide-based drugs continues to expand expeditiously. It is estimated that the global peptide drug market will be worth around USD 48.04 billion by 2025, with a compound annual growth rate of 9.4%. In this review, the current state of art of peptide-based therapeutics with special interest on tumour targeting peptides has been discussed. Moreover, various active targeting strategies such as the use functionalised peptides or peptide analogs are also elaborated.

Current approaches and future prospects of nanofibers: a special focus on antimicrobial drug delivery.

Antibacterial nanofibers have a great potential for effective treatment of infections. They act as drug reservoir systems that release higher quantities of antibacterial agents/drug in a controlled manner at infection sites and prevent drug resistance, while concomitantly decreasing the systemic toxicity. With this drug delivery system, it is also possible to achieve multiple drug entrapment and also simultaneous or sequential release kinetics at the site of action. Therefore, advances in antibacterial nanofibers as drug delivery systems were overviewed within this article. Recently published data on antibacterial drug delivery was also summarised to provide a view of the current state of art in this field. Although antibacterial use seems to be limited and one can ask that 'what is left to be discovered?'; recent update literatures in this field highlighted the use of nanofibers from very different perspectives. We believe that readers will be benefiting this review for enlightening of novel ideas.

Current status of micro/nanomotors in drug delivery.

Synthetic micro/nanomotors (MNMs) are novel, self-propelled nano or microscale devices that are widely used in drug transport, cell stimulation and isolation, bio-imaging, diagnostic and monitoring, sensing, photocatalysis and environmental remediation. Various preparation methods and propulsion mechanisms make MNMs "tailormade" nanosystems for the intended purpose or use. As the one of the newest members of nano carriers, MNMs open a new perspective especially for rapid drug transport and gene delivery. Although there exists limited number of in-vivo studies for drug delivery purposes, existence of in-vitro supportive data strongly encourages researchers to move on in this field and benefit from the manoeuvre capability of these novel systems. In this article, we reviewed the preparation and propulsion mechanisms of nanomotors in various fields with special attention to drug delivery systems.

Composite nanofibers incorporating alpha lipoic acid and atorvastatin provide neuroprotection after peripheral nerve injury in rats.

Despite the new treatment strategies within the last 30 years, peripheral nerve injury (PNI) is still a worldwide clinical problem. The incidence rate of PNIs is 1 in 1000 individuals per year. In this study, we designed a composite nanoplatform for dual therapy in peripheral nerve injury and investigated the in-vivo efficacy in rat sciatic nerve crush injury model. Alpha-lipoic acid (ALA) was loaded into poly lactic-co-glycolic acid (PLGA) electrospun nanofibers which would release the drug in a faster manner and atorvastatin (ATR) loaded chitosan (CH) nanoparticles were embedded into PLGA nanofibers to provide sustained release. Sciatic nerve crush was generated via Yasargil aneurism clip with a holding force of 50 g/cm2. Nanofiber formulations were administered to the injured nerve immediately after trauma. Functional recovery of operated rat hind limb was evaluated using the sciatic functional index (SFI), extensor postural thrust (EPT), withdrawal reflex latency (WRL) and Basso, Beattie, and Bresnahan (BBB) test up to one month in the post-operative period at different time intervals. In addition to functional recovery assessments, ultrastructural and biochemical analyses were carried out on regenerated nerve fibers. L-929 mouse fibroblast cell line and B35 neuroblastoma cell line were used to investigate the cytotoxicity of nanofibers before in-vivo experiments. The neuroprotection potential of these novel nanocomposite fiber formulations has been demonstrated after local implantation of composite nanofiber sheets incorporating ALA and ATR, which contributed to the recovery of the motor and sensory function and nerve regeneration in a rat sciatic nerve crush injury model.

A Snapshot on the Current Status of Alzheimer's Disease, Treatment Perspectives, in-Vitro and in-Vivo Research Studies and Future Opportunities.

Alzheimer's Disease (AD) is one of the most challenging diseases faced by humankind. AD is still not classified as curable because of the complex structure of pathologies underlying it. As the mean life expectancy of the world population constantly increases, the prevalence of AD and treatment costs for AD also grow rapidly. Current state of the art for AD treatment mainly consists of palliative therapy aimed at providing symptomatic relief and improving the standard of living in patients with AD. However, different research groups are working on more effective and safe drug delivery options aimed at both symptomatic relief and treatment of the underlying mechanisms. In this review, the current prevalence of AD, health costs, pathologies, and available treatment options including the ones in the market and/or under trial have been reviewed. Data in the existing literature have been presented, and future opportunities have been discussed. It is our belief that these nanotechnological products provide the required efficacy and safety profiles to enable these formulations go through phase studies and enter the market after regulatory authority approval, as with cancer. Last, but not the least the metabolomic studies will be providing useful informative data on the early diagnosis of AD, thus may be clinical implications might be delayed with the administration of therapeutic agents at the initial state of the disease.

Localized drug delivery with mono and bilayered mucoadhesive films and wafers for oral mucosal infections.

Local drug delivery into oral cavity offers many advantages over systemic administration in treatment of the oral infections. In this study, monolayer and bilayered mucoadhesive film and wafer formulations were developed as local drug delivery platforms using chitosan and hydroxypropyl methylcellulose (HPMC). Cefuroxime axetil (CA) was used as the model drug. Surface morphology, mechanical strength, water uptake, in vitro adhesion, disintegration and in vitro release properties of the formulations were investigated. Furthermore, antimicrobial activity of the formulations was evaluated against E. coli and S. aureus. HPMC based formulations were found to disintegrate within <30 min whereas chitosan based formulations remained intact up to 6 h. Significantly higher drug release was obtained with wafer formulations. Antimicrobial activity was found to increase in presence of chitosan, and HPMC was also observed to contribute to this action. Bilayered wafer formulation, with adhesive chitosan backing layer and HPMC based drug loaded layer, providing prolonged drug release and suitable adhesive properties, with suitable mechanical strength, would be suggested as a promising local delivery system for treatment of the infections in the oral cavity.

Molecular dynamics, thermodynamic, and mutational binding studies for tumor-specific LyP-1 in complex with p32.

Recent studies in tumor homing peptides have shown the specificity of LyP-1 (CGNKRTRGC) to tumor lymphatics. In this present work, we evaluated the possible interactions between cyclic LyP-1 and its receptor, p32, with molecular dynamics and docking studies in order to lead the design of novel LyP-1 derivatives, which could bind to p32 more effectively and perform enhanced antitumor effect. The total binding enthalpy energies have been obtained by MM-PBSA thermodynamic computations and the favorability of p32.LyP-1 complex in water has been shown by explicit water MD computations. The last 30 ns of molecular dynamics trajectory have shown the strong interaction of LyP-1 with the inner surface chains of p32, especially with chains B and C. ALA-SCAN mutagenesis studies have indicated the considerable influence of Asn3, Lys4, Arg5, and Arg7 amino acid residues on the specific binding of LyP-1. Within the knowledge of the critical role of p32 receptor in cancer cell metabolism, this study can lead to further developments in anticancer therapy by targeting p32 with LyP-1 derivatives as active targeting moiety. This data can also be applied for the development of new drug delivery systems in which LyP-1 can be used for its targeting and anticancer properties.

Design and in vitro evaluation of tenofovir-loaded vaginal gels for the prevention of HIV infections.

Infection with the human immunodeficiency virus (HIV) is affecting women disproportionally with increasing incidence rates over the last decades. Tenofovir is one of the most commonly used antiretroviral agents, which belongs to the nucleoside/nucleotide reverse transcriptase inhibitor family, for the prevention of HIV acquisition. In scope of this study, a thermogelling system containing tenofovir-loaded chitosan nanoparticles for the controlled release of tenofovir was developed and characterized. The in vitro release studies have shown that the burst release effect was decreased to 27% with f-TFV CS NPs-Gel. Gelation temperature of developed formulation was found as 26.6 ± 0.2 °C, which provides ease of administration while gelation occurs after the administration to the vagina. The work of adhesion values was used as parameters for comparison of mucoadhesive performance and the mucoadhesion of f-TFV CS NPs-Gel was found as 0.516 ± 0.136 N.s at 37 °C. The biocompatibility of blank formulations was evaluated by cell viability studies using L929 cells, in which Gel + CS NPs formulation was found to be safe with 82.4% and 90.2% cell viability for 1:16 and 1:32 dilutions, respectively. In conclusion, an improved tenofovir containing vaginal gel formulation was successfully developed and evaluated for preventing HIV transmission.

Design and In Vitro Evaluation of Bispecific Complexes and Drug Conjugates of Anticancer Peptide, LyP-1 in Human Breast Cancer.

PURPOSE: LyP-1, a nine-amino-acid tumor homing peptide, selectively binds to its cognate receptor, p32. Overexpression of p32 in certain tumors should allow use of LyP-1 as a targeting agent for the delivery of therapeutic or diagnostic agents. Peptide conjugates are developed for enhanced pre-targeting of MDA-MB-231 breast cancer cells with peptide-antibody bispecific complexes and targeting with multiple-drug/-fluorophore-conjugated nano-polymers. METHODS: LyP-1-anti-DTPA bispecific antibody complexes (LyP-1-bsAbCx) were generated by conjugation of anti-DTPA antibody and LyP-1. LyP-1-doxorubicin (Dox), Dox-DTPA-succinyl-polylysine (Dox-DSPL), Dox-DSPL-LyP-1, DTPA-Dox-poly glutamic acid (D-Dox-PGA) or DTPA-rhodamine conjugated polylysine (DSPL-RITC) were prepared. In vitro therapeutic efficacy and targeting by immunofluorescence in MDA-MB-231 breast cancer cells were assessed with Dox-LyP-1. Immunofluorescence visualization of cancer cells was evaluated after pretargeting with LyP-1-bsAbCx and targeting with DSPL-RITC. RESULTS: Cytotoxicity of Dox-LyP-1 conjugates was significantly greater than free doxorubicin (p < 0.0001). For fluorescent-labeled LyP-1, internalization occurred in 30 min in tumor cells. Fluorescence intensity of two-step targeted cells showed that pretargeting with LyP-1-bsAbC, followed by targeting with DSPL-RITC was greater than non-pretargeted DSPL-RITC (p < 0.05). CONCLUSIONS: Peptide-conjugates are effective targeting agents for MDA-MB-231 breast cancer cells in culture. LyP-1-bsAbCx and Dox-LyP-1 conjugates may allow development of novel targeted cancer therapy and diagnosis.