Surface-engineered nanoliposomes with lipidated and non-lipidated peptide-dendrimeric scaffold for efficient transdermal delivery of a therapeutic agent: Development, characterization, toxicological and preclinical performance analyses

Smart Physical-Based Transdermal Drug Delivery System:Towards Intelligence and Controlled Release

Transdermal drug delivery systems based on physical principles have provided a stable, efficient, and safe strategy for disease therapy. However, the intelligent device with real-time control and precise drug release is required to enhance treatment efficacy and improve patient compliance. This review summarizes the recent developments, application scenarios, and drug release characteristics of smart transdermal drug delivery systems fabricated with physical principle. Special attention is paid to the progress of intelligent design and concepts in of physical-based transdermal drug delivery technologies for real-time monitoring and precise drug release. In addition, facing with the needs of clinical treatment and personalized medicine, the recent progress and trend of physical enhancement are further highlighted for transdermal drug delivery systems in combination with pharmaceutical dosage forms to achieve better transdermal effects and facilitate the development of smart medical devices. Finally, the next generation and future application scenarios of smart physical-based transdermal drug delivery systems are discussed, a particular focus in vaccine delivery and tumor treatment.

Ameliorative anticancer effect of dendrimeric peptide modified liposomes of letrozole: In vitro and in vivo performance evaluations

Letrozole (LTZ) loaded dendrimeric nano-liposomes were prepared for targeted delivery to breast cancer cells. Surface modification with cationic peptide dendrimers (PDs) and a cancer specific ligand, transferrin (Tf), was attempted. Arginine-terminated PD (D-1) and Arginine-terminated, lipidated PD (D-2) were synthesized using Solid Phase Peptide Synthesis, purified by preparative HPLC and characterized using 1HNMR, MS and DSC analyses. Surface modification of drug loaded liposomes with Tf and/or PD was carried out. Formulations were characterized using FTIR, DSC, 1HNMR, XRD and TEM. Tf-conjugated LTZ liposomes (LTf) and Tf/D-2-conjugated LTZ liposomes (LTfD-2) showed greater cytotoxic potential (IC50 = 95.03 µg/mL and 23.75 µg/mL respectively) with enhanced cellular uptake in MCF7 cells compared to plain LTZ. Blocking studies of Tf (Tf-receptor mediated internalization) revealed decreased uptake of LTf and LTfD-2 confirming the role of Tf in uptake of Tf-conjugated liposomes. Intravenous treatment with LTfD-2 caused highest reduction in tumor volumes of female BALB/c-nude mice (145 mm3) compared to plain LTZ (605 mm3) and unconjugated LTZ liposomes (LP) (300 mm3). In vivo biodistribution studies revealed higher fluorescence in tumor tissue and liver of LTfD-2 treated mice than LTf or LP treatment. Immunohistochemical studies revealed greater apoptotic potential of LTfD-2 as indicated by TUNEL assay and ROS detection assay. The study reveals the superior therapeutic efficacy of the developed LTZ liposomal nanocarriers using PDs to enhance the transfection efficiency in addition to modifying the surface characteristics by attaching a targeting ligand for active drug targeting to breast cancer cells.

Anti-CD4 antibody and dendrimeric peptide based targeted nano-liposomal dual drug formulation for the treatment of HIV infection

AIMS

Development and characterization of LAM and DTG loaded liposomes conjugated anti-CD4 antibody and peptide dendrimer (PD2) to improve the therapeutic efficacy and to achieve targeted treatment for HIV infection.

MAIN METHODS

A 2-level full factorial design was used to optimize the preparation of dual drug loaded liposomes. Optimized dual drug loaded ligand conjugated liposomes were assessed for their cytotoxicity and cell internalization on TZM-bl cells. Anti-HIV efficiency of the dual drug loaded liposomes were screened for their inhibitory potential in TZM-bl cells and the activities were confirmed using Peripheral Blood Mononuclear Cells (PBMCs).

KEY FINDINGS

The particle size of the optimized dual drug-loaded liposomes was 133.7 ± 4.04 nm, and the spherical morphology of the liposomes was confirmed by TEM analysis. The entrapment efficiency was 34 ± 4.9 % and 54 ± 1.8 % for LAM and DTG, respectively, and a slower in vitro release of LAM and DTG was observed when entrapped into liposomes. The cytotoxicity of the dual drug loaded liposomes was similar to the cytotoxicity of free drug solutions. Conjugation of anti-CD4 antibody and PD2 did not significantly influence the cytotoxicity but it enhanced the uptake of liposomes into the cells. Conjugated dual drug loaded liposomes exhibited better HIV inhibition with lower IC50 values (0.0003 ± 0.0002 μg/mL) compared to their free drug solutions (0.002 ± 0.001 μg/mL). The liposomal formulations have shown similar activities in both screening and confirmatory cell-based assays.

SIGNIFICANCE

The results demonstrated the cell targeting ability of dual drug loaded liposomes conjugated with anti-CD4 antibody and peptide dendrimer. Conjugated liposomes also improved anti-HIV efficiency of LAM and DTG.

Targeted Delivery of 5-Fluorouracil and Sonidegib via Surface-Modified ZIF-8 MOFs for Effective Basal Cell Carcinoma Therapy

The therapeutic effectiveness of the most widely used anticancer drug 5-fluorouracil (5-FU) is constrained by its high metabolism, short half-life, and rapid drug resistance after chemotherapy. Although various nanodrug delivery systems have been reported for skin cancer therapy, their retention, penetration and targeting are still a matter of concern. Hence, in the current study, a topical gel formulation that contains a metal-organic framework (zeolitic imidazole framework; ZIF-8) loaded with 5-FU and a surface modified with sonidegib (SDG; acting as a therapeutic agent as well as a targeting ligand) (5-FU@ZIF-8 MOFs) is developed against DMBA-UV-induced BCC skin cancer in rats. The MOFs were prepared using one-pot synthesis followed by post drug loading and SDG conjugation. The optimized MOFs were incorporated into hyaluronic acid-hydroxypropyl methyl cellulose gel and further subjected to characterization. Enhanced skin deposition of the 5-FU@ZIF-8-SDG MOFs was observed using ex vivo skin permeation studies. Confocal laser microscopy studies showed that 5-FU@ZIF-8-SDG MOFs permeated the skin via the transfollicular pathway. The 5-FU@ZIF-8-SDG MOFs showed stronger cell growth inhibition in A431 cells and good biocompatibility with HaCaT cells. Histopathological studies showed that the efficacy of the optimized MOF gels improved as the epithelial cells manifested modest hyperplasia, nuclear pleomorphism, and dyskeratosis. Additionally, immunohistochemistry and protein expression studies demonstrated the improved effectiveness of the 5-FU@ZIF-8-SDG MOFs, which displayed a considerable reduction in the expression of Bcl-2 protein. Overall, the developed MOF gels showed good potential for the targeted delivery of multifunctional MOFs in topical formulations for treating BCC cancer.

Nanoparticle-mediated active and passive drug targeting in oral squamous cell carcinoma: current trends and advances

Oral squamous cell carcinoma (OSCC) is an invasive and highly malignant cancer with significant morbidity and mortality. Existing treatments including surgery, chemotherapy and radiation have poor overall survival rates and prognosis. The intended therapeutic effects of chemotherapy are limited by drug resistance, systemic toxicity and adverse effects. This review explores advances in OSCC treatment, with a focus on lipid-based platforms (solid lipid nanoparticles, nanostructured lipid carriers, lipid-polymer hybrids, cubosomes), polymeric nanoparticles, self-assembling nucleoside nanoparticles, dendrimers, magnetic nanovectors, graphene oxide nanostructures, stimuli-responsive nanoparticles, gene therapy, folic acid receptor targeting, gastrin-releasing peptide receptor targeting, fibroblast activation protein targeting, urokinase-type plasminogen activator receptor targeting, biotin receptor targeting and transferrin receptor targeting. This review also highlights oncolytic viruses as OSCC therapy candidates.

Nanotechnology-based mucoadhesive and mucus-penetrating drug-delivery systems for transbuccal drug delivery

Buccal drug-delivery systems present a promising approach for the drug delivery to the buccal mucosa, addressing oral cavity-specific problems, enabling systemic delivery and minimizing adverse effects on biological systems. Numerous strategies have been proposed to load drug-containing nanoparticles (NPs) to the buccal mucosa for local and systemic applications. There has been considerable interest in the development of mucoadhesive buccal formulations, particularly hydrogel composites utilizing mucoadhesive films incorporating NPs. Drug permeability and controlled drug release through buccal drug delivery continues to pose a challenge despite the availability of various remedies. This review highlights the need for, mechanisms and latest advances in NP-based transbuccal drug delivery with a focus on various pathological disorders and examples and limitations of the different methods.

Solvent Free Twin Screw Processed Silybin Nanophytophospholipid: In Silico, In Vitro and In Vivo Insights

Silybin (SIL) is a polyphenolic phytoconstituent that is commonly used to treat liver disorders. It is difficult to fabricate an orally delivered SIL product due to its low oral bioavailability (0.95%). Therefore, the current research focusses on the development of a novel composition of a phospholipid complex, termed as nanophytophospholipid, of SIL by employing a unique, solvent-free Twin Screw Process (TSP), with the goal of augmenting the solubility and bioavailability of SIL. The optimised SIL-nanophytophospholipid (H6-SNP) was subjected to physicochemical interactions by spectrometry, thermal, X-ray and electron microscopy. The mechanism of drug and phospholipid interaction was confirmed by molecular docking and dynamics studies. Saturation solubility, in vitro dissolution, ex vivo permeation and preclinical pharmacokinetic studies were also conducted. H6-SNP showed good complexation efficiency, with a high practical yield (80%). The low particle size (334.7 ± 3.0 nm) and positively charged zeta potential (30.21 ± 0.3 mV) indicated the immediate dispersive nature of H6-SNP into nanometric dimensions, with good physical stability. Further high solubility and high drug release from the H6-SNP was also observed. The superiority of the H6-SNP was demonstrated in the ex vivo and preclinical pharmacokinetic studies, displaying enhanced apparent permeability (2.45-fold) and enhanced bioavailability (1.28-fold). Overall, these findings indicate that not only can phospholipid complexes be formed using solvent-free TSP, but also that nanophytophospholipids can be formed by using a specific quantity of lipid, drug, surfactant, superdisintegrant and diluent. This amalgamation of technology and unique composition can improve the oral bioavailability of poorly soluble and permeable phytoconstituents or drugs.

Quality by Design steered Development of Niclosamide Loaded Liposomal Thermogel for Melanoma: In vitro and Ex vivo Evaluation

Melanoma is the most malignant form of skin cancer across the globe. Conventional therapies are currently ineffective which could be attributed to the rampant chemo-resistance, metastasis, inability to cross the skin barriers and accumulate within the tumor microenvironment. This advent brings in the principles of drug repurposing by repositioning Niclosamide (NIC), an anthelmintic drug for skin cancer. Incorporation into the liposomes facilitated enhanced melanoma cell uptake and apoptosis. Cytotoxicity studies revealed 1.756-fold enhancement in SK-MEL-28 cytotoxicity by NIC-loaded liposomes compared to free drug. Qualitative and quantitative cell internalization indicated greater drug uptake within the melanoma cells illustrating the efficacy of liposomes as efficient carrier systems. Nuclear staining showed blebbing and membrane shrinkage. Elevated ROS levels and apoptosis shown by DCFDA and acridine orange-ethidium bromide staining revealed greater melanoma cell death by liposomes compared to free drug. Incorporating NIC liposomes into the thermogel system restricted the liposomes as a depot onto the upper skin layers. Sustained zero order release up to 48 h with liposomes and 23.58-fold increase in viscosity led to the sol-to-gel transition at 33℃ was observed with liposomal thermogel. Ex vivo gel permeation studies revealed that C-6 loaded liposomes incorporated within the thermogel successfully formed a depot over the upper skin layer for 6 h to prevent transdermal delivery and systemic adverse effects. Thus, it could be concluded that NIC loaded liposomal thermogel system could be an efficacious therapeutic alternative for the management of melanoma.

Development of Lipidic Nanoplatform for Intra-Oral Delivery of Chlorhexidine: Characterization, Biocompatibility, and Assessment of Depth of Penetration in Extracted Human Teeth

Microorganisms are the major cause for the failure of root canal treatment, due to the penetration ability within the root anatomy. However, irrigation regimens have at times failed due to the biofilm mode of bacterial growth. Liposomes are vesicular structures of the phospholipids which might help in better penetration efficiency into dentinal tubules and in increasing the antibacterial efficacy. Methods: In the present work, chlorhexidine liposomes were formulated. Liposomal chlorhexidine was characterized by size, zeta potential, and cryo-electron microscope (Cryo-EM). Twenty-one single-rooted premolars were extracted and irrigated with liposomal chlorhexidine and 2% chlorhexidine solution to evaluate the depth of penetration. In vitro cytotoxicity study was performed for liposomal chlorhexidine on the L929 mouse fibroblast cell line. Results: The average particle size of liposomes ranged from 48 ± 4.52 nm to 223 ± 3.63 nm with a polydispersity index value of <0.4. Cryo-EM microscopic images showed spherical vesicular structures. Depth of penetration of liposomal chlorhexidine was higher in the coronal, middle, and apical thirds of roots compared with plain chlorhexidine in human extracted teeth when observed under the confocal laser scanning microscope. The pure drug exhibited a cytotoxic concentration at which 50% of the cells are dead after a drug exposure (IC50) value of 12.32 ± 3.65 µg/mL and 29.04 ± 2.14 µg/mL (on L929 and 3T3 cells, respectively) and liposomal chlorhexidine exhibited an IC50 value of 37.9 ± 1.05 µg/mL and 85.24 ± 3.22 µg/mL (on L929 and 3T3 cells, respectively). Discussion: Antimicrobial analysis showed a decrease in colony counts of bacteria when treated with liposomal chlorhexidine compared with 2% chlorhexidine solution. Nano-liposomal novel chlorhexidine was less cytotoxic when treated on mouse fibroblast L929 cells and more effective as an antimicrobial agent along with higher penetration ability.

Overcoming skin barriers through advanced transdermal drug delivery approaches

Upon exhaustive research, the transdermal drug delivery system (TDDS) has appeared as a potential, well-accepted, and popular approach to a novel drug delivery system. Ease of administration, easy handling, minimum systemic exposure, least discomfort, broad flexibility and tunability, controlled release, prolonged therapeutic effect, and many more perks make it a promising approach for effective drug delivery. Although, the primary challenge associated is poor skin permeability. Skin is an intact barrier that serves as a primary defense mechanism to preclude any foreign particle's entry into the body. Owing to the unique anatomical framework, i.e., compact packing of stratum corneum with tight junction and fast anti-inflammatory responses, etc., emerged as a critical physiological barrier for TDDS. Fusion with other novel approaches like nanocarriers, specially designed transdermal delivery devices, permeation enhancers, etc., can overcome the limitations. Utilizing such strategies, some of the products are under clinical trials, and many are under investigation. This review explores all dimensions that overcome poor permeability and allows the drug to attain maximum potential. The article initially compiles fundamental features, components, and design of TDDS, followed by critical aspects and various methods, including in vitro, ex vivo, and in vivo methods of assessing skin permeability. The work primarily aimed to highlight the recent advancement in novel strategies for effective transdermal drug delivery utilizing active methods like iontophoresis, electroporation, sonophoresis, microneedle, needleless jet injection, etc., and passive methods such as the use of liposomes, SLN, NLC, micro/nanoemulsions, dendrimers, transferosomes, and many more nanocarriers. In all, this compilation will provide a recent insight on the novel updates along with basic concepts, the current status of clinical development, and challenges for the clinical translation of TDDS.

The technology of transdermal delivery nanosystems: from design and development to preclinical studies

Transdermal administration has gained much attention due to the remarkable advantages such as patient compliance, drug escape from first-pass elimination, favorable pharmacokinetic profile and prolonged release properties. However, the major limitation of these systems is the limited skin penetration of the stratum corneum, the skin's most important barrier, which protects the body from the insertion of substances from the environment. Transdermal drug delivery systems are aiming to the disruption of the stratum corneum in order for the active pharmaceutical ingredients to enter successfully the circulation. Therefore, nanoparticles are holding a great promise because they can act as effective penetration enhancers due to their small size and other physicochemical properties that will be analyzed thoroughly in this report. Apart from the investigation of the physicochemical parameters, a comparison between the different types of nanoparticles will be performed. The complexity of skin anatomy and the unclear mechanisms of penetration should be taken into consideration to reach some realistic conclusions regarding the way that the described parameters affect the skin permeability. To the best of the authors knowledge, this is among the few reports on the literature describing the technology of transdermal delivery systems and how this technology affects the biological activity.

Transfersomes as alternative topical nanodosage forms for the treatment of skin disorders

Topical drug delivery is a promising approach to treat different skin disorders. However, it remains a challenge mainly due to the nature and rigidity of the nanosystems, which limit deep skin penetration, and the unsuccessful demonstration of clinical benefits; greater penetration by itself, does not ensure pharmacological success. In this context, transfersomes have appeared as promising nanosystems; deformability, their unique characteristic, allows them to pass through the epidermal microenvironment, improving the skin drug delivery. This review focuses on the comparison of transfersomes with other nanosystems (e.g., liposomes), discusses recent therapeutic applications for the topical treatment of different skin disorders and highlights the need for further studies to demonstrate significant clinical benefits of transfersomes compared with conventional therapies.

Development and preclinical evaluation of microneedle-assisted resveratrol loaded nanostructured lipid carriers for localized delivery to breast cancer therapy

Resveratrol (RVT) is one of the potent anticancer phytochemicals which has shown promising potential for breast cancer therapy. However, its short half-life and low bioavailability is a major hurdle in its effective use. In this study, we have developed nanostructured lipid carriers (NLCs) of RVT to enable localized delivery of the drug to the breast tissues using microneedle arrays to improve effectiveness. The NLCs were optimized using the Design of Experiments approach and characterized for their particle size, polydispersity index, zeta potential and entrapment efficiency. The RVT-NLCs delivered using microneedle array 1200 showed a higher permeation of RVT across the skin with lower skin retention compared to pure RVT. Further, RVT-NLCs showed higher anticancer activity on MDA-MB-231 breast cancer cell lines and enhanced internalization compared to pure RVT. Moreover, the RVT-NLCs were found to inhibit the migration of MDA-MB-231 breast cancer cell lines. Preclinical studies in rats showed that RVT-NLCs delivered via microneedles demonstrated a remarkable increase in the Cmax, Tmax and AUC0-inf, and a higher localization in breast tissue compared to pure RVT administered orally. These results suggests that the RVT-NLCs administered by microneedle array system is an effective strategy for the local delivery of RVT for breast cancer therapy.

Cationic liposomes mediated transdermal delivery of meloxicam and ketoprofen: Optimization of the composition, in vitro and in vivo assessment of efficiency

New liposomes modified with pyrrolidinium surfactants containing a hydroxyethyl fragment (C_nPB, n = 12, 14, 16) were prepared for transdermal delivery of non-steroidal anti-inflammatory drugs. In order to obtain the optimal composition, the surfactant/lipid molar ratio (0.02/1; 0.029/1; 0.04/1) and the amphiphile hydrocarbon tail length were varied. Rhodamine B was loaded in all formulations, while meloxicam and ketoprofen in selected ones. For liposomes studied the hydrodynamic diameter was in the range of 80-130 nm, the zeta potential ranged from +35 to +50 mV, EE was 75-99%. Liposome modification leads to a prolonged release of the rhodamine B (up to 10-12 h) and faster release of non-steroidal drugs (up to 7-8 h) in vitro. The ability to cross the skin barrier using Franz cells was investigated for liposomal meloxicam and ketoprofen. The total amount of meloxicam and ketoprofen passed through the Strat-M® membranes during 51 h was 51-114 μg/cm² and 87-105 μg/cm² respectively. The evaluation of transdermal diffusion ex vivo showed that total amount of liposomal ketoprofen passed through the skin during 51 h was 140-162 μg/cm². Liposomes modified with C₁₆PB were found as the most effective inflammation reducing formulation in the carrageenan edema model of rat paw.