Elastic Liposomes Containing Calcium/Magnesium Ferrite Nanoparticles Coupled with Gold Nanorods for Application in Photothermal Therapy

This work reports on the design, development, and characterization of novel magneto-plasmonic elastic liposomes (MPELs) of DPPC:SP80 (85:15) containing Mg0.75Ca0.25Fe2O4 nanoparticles coupled with gold nanorods, for topical application of photothermal therapy (PTT). Both magnetic and plasmonic components were characterized regarding their structural, morphological, magnetic and photothermal properties. The magnetic nanoparticles display a cubic shape and a size (major axis) of 37 ± 3 nm, while the longitudinal and transverse sizes of the nanorods are 46 ± 7 nm and 12 ± 1.6 nm, respectively. A new methodology was employed to couple the magnetic and plasmonic nanostructures, using cysteine as bridge. The potential for photothermia was evaluated for the magnetic nanoparticles, gold nanorods and the coupled magnetic/plasmonic nanoparticles, which demonstrated a maximum temperature variation of 28.9 °C, 33.6 °C and 37.2 °C, respectively, during a 30 min NIR-laser irradiation of 1 mg/mL dispersions. Using fluorescence anisotropy studies, a phase transition temperature (Tm) of 35 °C was estimated for MPELs, which ensures an enhanced fluidity crucial for effective crossing of the skin layers. The photothermal potential of this novel nanostructure corresponds to a specific absorption rate (SAR) of 616.9 W/g and a maximum temperature increase of 33.5 °C. These findings point to the development of thermoelastic nanocarriers with suitable features to act as photothermal hyperthermia agents.

Luteolin-Loaded Elastic Liposomes for Transdermal Delivery to Control Breast Cancer: In Vitro and Ex Vivo Evaluations

The study aimed to prepare and optimize luteolin (LUT)-loaded transdermal elastic liposomes (LEL1-LEL12), followed by in vitro and ex vivo evaluations of their ability to control breast cancer. Various surfactants (Span 60, Span 80, and Brij 35), and phosphatidyl choline (PC) as a lipid, were used to tailor various formulation as dictated by “Design Expert^® software (DOE). These were characterized for size, polydispersity index (PDI), and zeta potential. The optimized formulation (OLEL1) was selected for comparative investigations (in vitro and ex vivo) against lipo (conventional liposomes) and drug suspension (DS). Moreover, the in vitro anticancer activity of OLEL1 was compared against a control using MCF-7 cell lines. Preliminary selection of the suitable PC: surfactant ratio for formulations F1–F9 showed relative advantages of Span 80. DOE suggested two block factorial designs with four center points to identify the design space and significant factors. OLEL1 was the most robust with high functional desirability (0.95), minimum size (202 nm), relatively high drug release, increased drug entrapment (92%), and improved permeation rate (~3270 µg/cm²) as compared with liposomes (~1536 µg/cm²) over 24 h. OLEL1 exhibited a 6.2- to 2.9-fold increase in permeation rate as compared with DS (drug solution). The permeation flux values of OLEL1, and lipo were found to be 136.3, 64 and 24.3 µg/h/cm², respectively. The drug disposition values were 670 µg, 473 µg and 148 µg, for OLEL1, lipo and DS, respectively. Thus, ex vivo parameters were significantly better for OLEL1 compared with lipo and DS which is attributed to the flexibility and deformability of the optimized formulation. Furthermore, OLEL1 was evaluated for anticancer activity and showed maximized inhibition as compared with DS. Thus, elastic liposomes may be a promising approach for improved transdermal delivery of luteolin, as well as enhancing its therapeutic efficacy in controlling breast cancer.

Development of a novel polymer-based carrier for deformable liposomes for the controlled dermal delivery of naringenin

In recent years, the incidence of skin cancer has increased worldwide, presenting a significant burden on healthcare services. Chemotherapy intervention is often not appropriate for all patients due to localized adverse effects on skin physiology. The aim of this study was, therefore, to consider the development of a novel phytochemical-based deformable liposomal formulation suspended in an aqueous gel for the controlled-release of naringenin. Naringenin is an antioxidant, free radical scavenger, anti-inflammatory agent, and immune system modulator thus may be potentially useful as a pharmacological anti-cancer agent. Formulated liposomes incorporating an increasing loading of Tween 20 (from 0% w/w to 10% w/w) demonstrated a significant decrease in deformability index (DI) (80.71 ± 2.02-59.17 ± 4.42 %), indicating an increase in elasticity. The release of naringenin over 24 h was directly affected by Tween-20 concentration, decreasing from 100.72%±4.98% to 79.53%±3.68% for 0% and 2% w/w Tween 20, respectively. Further, the incorporation of deformable liposomes into hydroxyethylcellulose (HEC) and hydroxypropyl methylcellulose (HPMC) gels resulting in a further retardation of naringenin release, 23.21%±1.17% and 19.83%±1.50%, respectively, over 24 h. Incubation of 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate-loaded liposomes with human dermal fibroblast (HDF) and keratinocyte cells demonstrated intracellular accumulation within 2 h, confirming deformable liposomes may be beneficial in improving drug penetration across dermal cells and would be valuable in emerging controlled-release formulations.

Experimental Design Based Optimization and Ex Vivo Permeation of Desmopressin Acetate Loaded Elastic Liposomes Using Rat Skin

The study aimed to develop elastic-liposome-based transdermal delivery of desmopressin acetate for enhanced permeation to control enuresis, central diabetes insipidus, and traumatic injury. Elastic liposomes (ELs)-loaded desmopressin acetate was prepared, optimized, and evaluated for improved transdermal permeation profiles using rat skin. Full factorial design with independent factors (X₁ for lipid and X₂ for surfactant) at three levels was used against four responses (Y₁, Y₂, Y₃, and Y₄) (dependent variables). Formulations were characterized for vesicle size, polydispersity index (PDI), zeta potential, % entrapment efficiency (% EE), in vitro drug release, in vitro hemolysis potential, ex vivo drug permeation and drug deposition (DD), and ex vivo vesicle–skin interaction using scanning electron microscopy studies. The optimized formulation ODEL1 based on desirability function was found to have vesicle size, % EE, % DR, and permeation flux values of 118.7 nm, 78.9%, 75.1%, and 5.3 µg/h·cm², respectively, which were close to predicted values. In vitro release profiles indicated slow and sustained delivery. Permeation flux values of ODEL1 and ODEL2 were 5.3 and 3.1 µg/h·cm², respectively, which are 7.5- and 4.4-fold higher as compared to DS (0.71 µg/h·cm²). The obtained flux was relatively higher than the clinical target value of the drug for therapeutic efficacy. Moreover, the DD value of ODEL1 was significantly higher than ODEL2 and DS. Hemocompatibility study confirmed safety concerns. Finally, vesicle–skin interaction corroborated mechanistic views of permeation through rat skin. Conclusively, the transdermal delivery may be a suitable alternative to oral and nasal delivery to treat nocturnal enuresis, central diabetes insipidus, hemophilia A and von Willebrand’s disease, and any traumatic injuries.

Development, Characterization, and Ex Vivo Assessment of Elastic Liposomes for Enhancing the Buccal Delivery of Insulin

Buccal drug delivery is a suitable alternative to invasive routes of drug administration. The buccal administration of insulin for the management of diabetes has received substantial attention worldwide. The main aim of this study was to develop and characterize elastic liposomes and assess their permeability across porcine buccal tissues. Sodium-cholate-incorporated elastic liposomes (SC-EL) and sodium-glycodeoxycholate-incorporated elastic liposomes (SGDC-EL) were prepared using the thin-film hydration method. The prepared liposomes were characterized and their ex vivo permeability attributes were investigated. The distribution of the SC-EL and SGDC-EL across porcine buccal tissues was evaluated using confocal laser scanning microscopy (CLSM). The SGDC-EL were the most superior nanocarriers since they significantly enhanced the permeation of insulin across porcine buccal tissues, displaying a 4.33-fold increase in the permeability coefficient compared with the insulin solution. Compared with the SC-EL, the SGDC-EL were better at facilitating insulin permeability, with a 3.70-fold increase in the permeability coefficient across porcine buccal tissue. These findings were further corroborated based on bioimaging analysis using CLSM. SGDC-ELs showed the greatest fluorescence intensity in buccal tissues, as evidenced by the greater shift of fluorescence intensity toward the inner buccal tissue over time. The fluorescence intensity ranked as follows: SGDC-EL > SC-EL > FITC–insulin solution. Conclusively, this study highlighted the potential nanocarriers for enhancing the buccal permeability of insulin.

Transdermal Immunization of Elastic Liposome-Laden Recombinant Chimeric Fusion Protein of P. falciparum (PfMSP-Fu24) Mounts Protective Immune Response

Transdermal immunization exhibits poor immunogenic responses due to poor permeability of antigens through the skin. Elastic liposomes, the ultradeformable nanoscale lipid vesicles, overcome the permeability issues and prove a versatile nanocarrier for transcutaneous delivery of protein, peptide, and nucleic acid antigens. Elastic liposome-mediated subcutaneous delivery of chimeric fusion protein (PfMSP-Fu24) of Plasmodium falciparum exhibited improved immunogenic responses. Elastic liposomes-mediated immunization of PfMSP-Fu24 conferred immunity to the asexual blood-stage infection. Present study is an attempt to compare the protective immune response mounted by the PfMSP-Fu24 upon administered through transdermal and intramuscular routes. Humoral and cell-mediated immune (CMI) response elicited by topical and intramuscularly administered PfMSP-Fu24-laden elastic liposomes (EL-PfMSP-Fu24) were compared and normalized with the vehicle control. Sizeable immune responses were seen with the transcutaneously immunized EL-PfMSP-Fu24 and compared with those elicited with intramuscularly administered antigen. Our results show significant IgG isotype subclass (IgG1and IgG3) response of specific antibody levels as well as cell-mediated immunity (CMI) activating factor (IFN-γ), a crucial player in conferring resistance to blood-stage malaria in mice receiving EL-PfMSP-Fu24 through transdermal route as compared to the intramuscularly administered formulation. Heightened immune response obtained by the vaccination of EL-PfMSP-Fu24 was complemented by the quantification of the transcript (mRNA) levels cell-mediated (IFN-γ, IL-4), and regulatory immune response (IL-10) in the lymph nodes and spleen. Collectively, elastic liposomes prove their immune-adjuvant property as they evoke sizeable and perdurable immune response against PfMSP-Fu24 and justify its potential for the improved vaccine delivery to inducing both humoral and CM immune response.

Intracellular uptake of EGCG-loaded deformable controlled release liposomes for skin cancer

Caucasian population groups have a higher propensity to develop skin cancer, and associated clinical interventions often present substantial financial burden on healthcare services. Conventional treatments are often not suitable for all patient groups as a result of poor efficacy and toxicity profiles. The primary objective of this study was to develop a deformable liposomal formulation, the properties of which being dictated by the surfactant Tween 20, for the dermal cellular delivery of epigallocatechin gallatein (EGCG), a compound possessing antineoplastic properties. The results demonstrated a significant (p ≤ 0.05) decrease in liposome deformability index (74 ± 8 to 37 ± 7) as Tween 20 loading increased from 0 to 10% w/w, indicating an increase in elasticity. EGCG release over 24-h demonstrated Tween 20 incorporation directly increased release from 13.7% ± 1.1% to 94.4% ± 4.9% (for 0 and 10% w/w Tween 20 respectively). Finally, we demonstrated DilC-loaded deformable liposomes were localized intracellularly within human dermal fibroblast and keratinocyte cells within 2 h. Thus, it was evident that deformable liposomes may aid drug penetration into dermal cells and would be useful in developing a controlled-release formulation.

Facilitated permeation of insulin across TR146 cells by cholic acid derivatives-modified elastic bilosomes

BACKGROUND

Buccal delivery of insulin is still a challenging issue for the researchers due to the presence of permeability barrier (buccal mucosa) in the buccal cavity. The main objective of this study was to investigate the safety, effectiveness, and potential of various liposomes containing different bile salts to improve the permeation of insulin across in vitro TR146 buccal cell layers.

METHODS

Elastic bilosomes containing soy lecithin and bile salt edge activators (sodium cholate [SC], sodium taurocholate [STC], sodium glycocholate [SGC], sodium deoxyglycocholate [SDGC], or sodium deoxytaurocholate [SDTC]) were fabricated by thin-film hydration method. The prepared liposomes were characterized, and in vitro permeation studies were performed. The fluorescein isothiocyanate-insulin-loaded elastic bilosomes were used to evaluate the quantitative and qualitative cellular uptake studies.

RESULTS

The prepared elastic bilosomes had a particle size and an entrapment efficiency of ~140-150 nm and 66%-78%, respectively. SDGC-lipo (SDGC-incorporated liposome) was observed to be the most superior with an enhancement ratio (ER) of 5.24 (P<0.001). The SC-incorporated liposome (SC-lipo) and SDTC-incorporated liposome (SDTC-lipo) also led to a significant enhancement with ERs of 3.20 and 3.10 (P<0.05), respectively, compared with insulin solution. These results were further supported by quantitative and qualitative cellular uptake studies performed employing fluorescence-activated cell sorting analysis and confocal microscopy, respectively. The relative median fluorescence intensity values of elastic bilosomes were counted in the order of SDGC-lipo > SC-lipo > SDTC-lipo > SGC-incorporated liposome > STC-incorporated liposome, and similarity in the permeability profile of the employed elastic bilosomes was noted.

CONCLUSION

This study presents the employment of various derivatives of cholic acid-loaded elastic bilosomes as a promising strategy to enhance the permeation of insulin through buccal route.

Elastic liposomes as novel carriers: recent advances in drug delivery

Elastic liposomes (EL) are some of the most versatile deformable vesicular carriers that comprise physiologically biocompatible lipids and surfactants for the delivery of numerous challenging molecules and have marked advantages over other colloidal systems. They have been investigated for a wide range of applications in pharmaceutical technology through topical, transdermal, nasal, and oral routes for efficient and effective drug delivery. Increased drug encapsulation efficiency, enhanced drug permeation and penetration into or across the skin, and ultradeformability have led to widespread interest in ELs to modulate drug release, permeation, and drug action more efficiently than conventional drug-release vehicles. This review provides insights into the versatile role that ELs play in the delivery of numerous drugs and biomolecules by improving drug release, permeation, and penetration across the skin as well as stability. Furthermore, it provides future directions that should ensure the widespread use of ELs across all medical fields.

Biomimetic Lipid-Based Nanosystems for Enhanced Dermal Delivery of Drugs and Bioactive Agents

Clinical utility of conventional oral therapies is limited by their inability to deliver therapeutic molecules at the local or targeted site, causing a variety of side effects. Transdermal delivery has made a significant contribution in the management of skin diseases with enhanced therapeutic activities over the past two decades. In the modern era, various biomimetic and biocompatible polymer-lipid hybrid systems have been used to augment the transdermal delivery of therapeutics such as dermal patches, topical gels, iontophoresis, electroporation, sonophoresis, thermal ablation, microneedles, cavitational ultrasound, and nano or microlipid vesicular systems. Nevertheless, the stratum corneum still represents the main barrier to the delivery of vesicles into the skin. Lipid based formulations applied to the skin are at the center of attention and are anticipated to be increasingly functional as the skin offers many advantages for the direction of such systems. Accordingly, this review provides an overview of the development of conventional to advanced biomimetic lipid vesicles for skin delivery of a variety of therapeutics, with special emphasis on recent developments in this field including the development of transferosomes, niosomes, aquasomes, cubosomes, and other new generation lipoidal carriers.

Tat peptide-admixed elastic liposomal formulation of hirsutenone for the treatment of atopic dermatitis in NC/Nga mice

BACKGROUND

The aim of the present study was to enhance a topical delivery of hirsutenone (HST), a naturally occuring immunomodulator, employing Tat peptide-admixed elastic liposomes (EL/T).

METHODS

HST-loaded EL, consisting of phosphatidylcholine and Tween 80 (85:15 w/w%), were prepared using thin film hydration method. By adding Tat peptide to EL (0.16 w/w%), EL/T were formulated. The in vitro skin permeation of HST was examined using a Franz diffusion cell mounted with depilated mouse skin. Lesions for atopic dermatitis (AD) were induced by a topical application of diphenylcyclopropenone to NC/Nga mice. Therapeutic improvements of AD were evaluated by clinical skin severity scores. Immunological analyses on inducible nitric oxide synthase and cyclooxygenase-2 levels in the skin and interleukin (IL)-4, IL-13, immunoglobulin E, and eosinophil levels in the blood were also performed.

RESULTS

EL systems were superior to conventional cream, revealing greater flux values in a permeation study. The addition of Tat peptide further increased the skin permeation of HST. In an efficacy study with AD-induced NC/Nga mice, an HST-containing EL/T formulation brought a significant improvement in both skin severity score and immune-related responses for the levels of nitric oxide synthase, cyclooxygenase-2, IL-4, IL-13, immunoglobulin E, and eosinophils.

CONCLUSION

A novel EL/T formulation was successfully developed for topical delivery of HST to treat AD.