Enhancement of Skin Permeation and Skin Immunization of Ovalbumin Antigen via Microneedles

The purpose of this study was to evaluate the use of different types of microneedles and doses of ovalbumin antigen for in vitro skin permeation and in vivo immunization. In vitro skin permeation experiments and confocal laser scanning microscopy revealed that hollow microneedles had a superior enhancing effect on skin permeation compared with a solid microneedle patch and untreated skin by efficiently delivering ovalbumin-fluorescein conjugate into the deep skin layers. The flux and cumulative amount of ovalbumin-fluorescein conjugate at 8 h after administering with various conditions could be ranked as follows: hollow MN; high dose > medium dose > low dose > MN patch; high dose > medium dose > low dose > untreated skin; high dose > medium dose > low dose > without ovalbumin-fluorescein conjugate. As the dose of ovalbumin-fluorescein conjugate was increased to 500 μg, the antigen accumulated in the skin to a greater extent, as evidenced by the increasing green fluorescence intensity. When the hollow microneedle was used for the delivery of ovalbumin into the skin of mice, it was capable of inducing a stronger immunoglobulin G immune response than conventional subcutaneous injection at the same antigen dose. Immunoglobulin G levels in the hollow MN group were 5.7, 11.6, and 13.3 times higher than those of the subcutaneous injection group for low, medium, and high doses, respectively. Furthermore, the mice immunized using the hollow microneedle showed no signs of skin infection or pinpoint bleeding. The results suggest that the hollow MN is an efficient device for delivering the optimal dose of antigen via the skin for successful immunization.

Development of a novel microemulsion for oral absorption enhancement of all-trans retinoic acid

This study was aimed to develop a novel microemulsion that contained oleth-5 as a surfactant to enhance the oral absorption of all-trans retinoic acid (ATRA). The prepared microemulsion was evaluated for its particle size, shape, zeta potential, in vitro release, in vitro intestinal absorption, intestinal membrane cytotoxicity and stability. The obtained microemulsion was spherical in shape with a particle size of <200 nm and a negative surface charge. The in vitro release of the ATRA-loaded microemulsion was best fit with the zero-order model. This microemulsion significantly improved the intestinal absorption of ATRA. Confocal laser scanning microscopy analysis using a fluorescent dye-loaded microemulsion also confirmed the intestinal absorption result. The intestinal membrane cytotoxicity of the ATRA-loaded microemulsion did not differ from an edible oil (fish oil). Stability testing showed that the ATRA-loaded microemulsion was more stable at 25°C than 40°C.

A combined approach of hollow microneedles and nanocarriers for skin immunization with plasmid DNA encoding ovalbumin

The aim of this study was to investigate the use of different types of microneedles (MNs) and nanocarriers for in vitro skin permeation and in vivo immunization of plasmid DNA encoding ovalbumin (pOVA). In vitro skin permeation studies indicated that hollow MNs had a superior enhancing effect on skin permeation compared with solid MN patches, electroporation (EP) patches, the combination of MN and EP patches, and untreated skin. Upon using hollow MNs combined with nanocarriers for pOVA delivery, the skin permeation was higher than for the delivery of naked pOVA, as evidenced by the increased amount of pOVA in Franz diffusion cells and immunoglobulin G (IgG) antibody responses. When the hollow MNs were used for the delivery of nanocarrier:pOVA complexes into the skin of mice, they induced a stronger IgG immune response than conventional subcutaneous (SC) injections. In addition, immunization of mice with the hollow MNs did not induce signs of skin infection or pinpoint bleeding. Accordingly, the hollow MNs combined with a nanocarrier delivery system is a promising approach for delivering pOVA complexes to the skin for promoting successful immunization.

Fabrication and Evaluation of Nanostructured Herbal Oil/Hydroxypropyl-β-Cyclodextrin/Polyvinylpyrrolidone Mats for Denture Stomatitis Prevention and Treatment

This work aims to develop the herbal oil-incorporated nanostructure mats with antifungal activity for the prevention and treatment of Candida-associated denture stomatitis. The nanofiber mats loaded with betel oil or clove oil were fabricated via electrospinning process. The morphologies and physicochemical properties of the herbal oil loaded nanofiber mats were examined using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and mechanical testing. The release characteristic, antifungal activity, and cytotoxicity were also investigated. The SEM images confirmed the homogeneous and smooth nanoscale fibers. The addition of the herbal oil into the nanofiber mats reduced the fiber diameters. The DSC and FT-IR results confirmed the presence of the oil in the nanofiber mats. The herbal oils can be released from the mats in a very fast manner and inhibit the growth of candida cells within only few minutes after contact. These nanofiber mats may be beneficial for the prevention and treatment of denture stomatitis.

Influence of sonophoresis on transdermal drug delivery of hydrophilic compound-loaded lipid nanocarriers

The effect of sonophoresis on the transdermal drug delivery of sodium fluorescein (NaFI)-loaded lipid nanocarriers such as liposomes (LI), niosomes (NI) and solid lipid nanoparticles (SLN) was investigated by confocal laser scanning microscopy (CLSM), fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results showed that SN decreased the skin penetration of NaFI-loaded SLN (6.32-fold) and NI (1.79-fold), while it increased the penetration of NaFI-loaded LI (5.36-fold). CLSM images showed the red fluorescence of the LI and NI bilayer on the superficial layer of the stratum corneum. However, the red fluorescent probe of the SLN was not visualized in the skin. FTIR results of the LI and NI with SN showed no effect on lipid stratum corneum ordering, suggesting that the fragment of bilayer vesicles might repair the damaged skin. For SLN, the strengthening of stratum corneum by covering the disrupted skin with solid lipids was shown. SEM images show disrupted carriers of all the formulations adsorbed onto the damaged skin. In conclusion, the SN changed the properties of both the skin surface and lipid nanocarrier, demonstrating that disrupted skin might be repaired by a disrupted nanocarrier.

Development and evaluation of N-naphthyl-N,O-succinyl chitosan micelles containing clotrimazole for oral candidiasis treatment

Clotrimazole (CZ)-loaded N-naphthyl-N,O-succinyl chitosan (NSCS) micelles have been developed as an alternative for oral candidiasis treatment. NSCS was synthesized by reductive N-amination and N,O-succinylation. CZ was incorporated into the micelles using various methods, including the dropping method, the dialysis method, and the O/W emulsion method. The size and morphology of the CZ-loaded micelles were characterized using dynamic light scattering measurements (DLS) and a transmission electron microscope (TEM), respectively. The drug entrapment efficiency, loading capacity, release characteristics, and antifungal activity against Candida albicans were also evaluated. The CZ-loaded micelles prepared using different methods differed in the size of micelles. The micelles ranged in size from 120 nm to 173 nm. The micelles prepared via the O/W emulsion method offered the highest percentage entrapment efficiency and loading capacity. The CZ released from the CZ-loaded micelles at much faster rate compared to CZ powder. The CZ-loaded NSCS micelles can significantly hinder the growth of Candida cells after contact. These CZ-loaded NSCS micelles offer great antifungal activity and might be further developed to be a promising candidate for oral candidiasis treatment.

Aligned Electrospun Polyvinyl Pyrrolidone/Poly ε-Caprolactone Blend Nanofiber Mats for Tissue Engineering

Electrospun nanofibrous materials are widely used in medical applications such as tissue engineering scaffolds, wound dressing material and drug delivery carriers. For tissue engineering scaffolds, the structure of the nanofiber is similar to extracellular matrix (ECM) which promotes the cell growth and proliferation. In the present study, the aligned nanofiber mats of polyvinyl pyrrolidone (PVP) blended poly [Formula: see text]-caprolactone (PCL) was successfully generated using electrospinning technique. The morphology of PVP/PCL nanofiber mats were characterized by scanning electron microspore (SEM). The chemical and crystalline structure of PVP/PCL nanofiber mats were analyzed using Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffactometer (PXRD). The water contact angle of mats was investigated. Cell culture studies using normal human fibroblasts (NHF) were performed to assess cell morphology, cell alignment and cell proliferation. The results indicated that the fiber were in nanometer range. The PVP/PCL was well dispersed in nanofiber mats and was in amorphous form. The water contact angle of PVP/PCL nanofiber mats was lower than PCL nanofiber mats. The PVP/PCL nanofiber mats exhibited good biocompatibility with NHF cells. In summary, the PVP/PCL nanofiber mats had potential to be used in tissue engineering and regenerative medicine.

Cationic niosomes an effective gene carrier composed of novel spermine-derivative cationic lipids: effect of central core structures

CONTEXT

Cationic niosomes formulated from Span 20, cholesterol (Chol) and novel spermine-based cationic lipids of multiple central core structures (di(oxyethyl)amino, di(oxyethyl)amino carboxy, 3-amino-1,2-dioxypropyl and 2-amino-1,3-dioxypropyl) were successfully prepared for improving transfection efficiency in vitro. The niosomes composed of spermine cationic lipid with central core structure of di(oxyethyl)amino revealed the highest gene transfection efficiency.

OBJECTIVES

To investigate the factors affecting gene transfection and cell viability including differences in the central core structures of cationic lipids, the composition of vesicles, molar ratio of cationic lipids in formulations and the weight ratio of niosomes to DNA.

METHODS

Cationic niosomes composed of nonionic surfactants (Span20), cholesterol and spermine-based cationic lipids of multiple central core structures were formulated. Gene transfection and cell viability were evaluated on a human cervical carcinoma cell line (HeLa cells) using pDNA encoding green fluorescent protein (pEGFP-C2). The morphology, size and charge were also characterized.

RESULTS AND DISCUSSION

High transfection efficiency was obtained from cationic niosomes composed of Span20:Chol:cationic lipid at the molar ratio of 2.5:2.5:0.5 mM. Cationic lipids with di(oxyethyl)amino as a central core structure exhibited highest transfection efficiency. In addition, there was also no serum effect on transfection efficiency.

CONCLUSIONS

These novel cationic niosomes may constitute a good alternative carrier for gene transfection.

Mechanistic study of decreased skin penetration using a combination of sonophoresis with sodium fluorescein-loaded PEGylated liposomes with d-limonene

The effect of low frequency sonophoresis (SN, 20 kHz) on the skin transport of sodium fluorescein (NaFI)-loaded liposomes was investigated. An in vitro skin penetration study in open and blocked hair follicles was performed, and confocal laser scanning microscopy and scanning electron microscopy were used to visualize the penetration pathways. The results showed that SN significantly increased the flux of NaFI solution, whereas it significantly decreased the flux of NaFI-loaded polyethylene glycol-coated (PEGylated) liposomes with D-limonene (PL-LI). SN did not significantly affect the flux of NaFI-loaded conventional liposomes and PEGylated liposomes. In the blocked follicles, the flux of NaFI-loaded PL-LI both with and without SN decreased, indicating that NaFI-loaded PL-LI penetrated the skin via the transfollicular pathway. A confocal laser scanning microscopy image showed that in the skin without SN, the fluorescence intensity of NaFI-loaded PL-LI was observed in the skin and along the length of hair inside the skin, whereas in the skin with applied SN, the fluorescence intensity was detected only on the top of hair outside the skin. From scanning electron microscopy images, SN dislocated the corneocytes and reduced the deposition of PL-LI around hair follicles. These results revealed that SN may partially plug hair follicle orifices and reduce percutaneous absorption through the follicular pathway.

Fabrication and In Vitro/In Vivo Performance of Mucoadhesive Electrospun Nanofiber Mats Containing α-Mangostin

This study aimed to fabricate mucoadhesive electrospun nanofiber mats containing α-mangostin for the maintenance of oral hygiene and reduction of the bacterial growth that causes dental caries. Synthesized thiolated chitosan (CS-SH) blended with polyvinyl alcohol (PVA) was selected as the mucoadhesive polymer. α-Mangostin was incorporated into the CS-SH/PVA solution and electrospun to obtain nanofiber mats. Scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and tensile strength testing were used to characterize the mats. The swelling degree and mucoadhesion were also determined. The nanofiber mats were further evaluated regarding their α-mangostin content, in vitro α-mangostin release, antibacterial activity, cytotoxicity, in vivo performance, and stability. The results indicated that the mats were in the nanometer range. The α-mangostin was well incorporated into the mats, with an amorphous form. The mats showed suitable tensile strength, swelling, and mucoadhesive properties. The loading capacity increased when the initial amount of α-mangostin was increased. Rapid release of α-mangostin from the mats was achieved. Additionally, a fast bacterial killing rate occurred at the lowest concentration of nanofiber mats when α-mangostin was added to the mats. The mats were less cytotoxic after use for 72 h. Moreover, in vivo testing indicated that the mats could reduce the number of oral bacteria, with a good mouth feel. The mats maintained the amount of α-mangostin for 6 months. The results suggest that α-mangostin-loaded mucoadhesive electrospun nanofiber mats may be a promising material for oral care and the prevention of dental caries.

Role of simplex lattice statistical design in the formulation and optimization of microemulsions for transdermal delivery

Microemulsions (ME) have gained attention as an alternative pharmaceutical formulation for transdermal delivery systems. However, the complicated relationships between various ME compositions (causal factors) and their characteristics (response variable) have not been fully comprehended. To overcome this problem, the design and development of ME for transdermal delivery was performed in our study using Design Expert(®) Software. The model formulations of ME were prepared according to the ME region obtained from pseudo-ternary phase diagrams using the simplex lattice design as an optimization technique. In this study, ketoprofen-loaded ME composed of oleic acid, Cremophor(®) RH40, ethanol and water were prepared, and their characteristics (e.g., size, charge, conductivity, pH, viscosity, drug content, loading capacity and skin permeation flux) were evaluated. The ME having an appropriate skin permeation flux was used as the basis for optimization. The skin permeation flux of the experimental ME was very close to the flux predicted by Design Expert(®) Software and was significantly greater than that for the commercial product. Possible mechanisms for the enhancement of the skin permeation of the ME were also investigated using Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD). This finding provided an understanding of the relationship between the causal factors and response variables, as shown in the response surfaces. Moreover, these results indicated that the simple lattice design was beneficial for the pharmaceutical development of ME for transdermal delivery.

Effect of liposomal fluidity on skin permeation of sodium fluorescein entrapped in liposomes

The purpose of this study was to investigate the effect of ultradeformable liposome components, Tween 20 and terpenes, on vesicle fluidity. The fluidity was evaluated by electron spin resonance spectroscopy using 5-doxyl stearic acid and 16-doxyl stearic acid as spin labels for phospholipid bilayer fluidity at the C5 atom of the acyl chain near the polar head group (hydrophilic region) and the C16 atom of the acyl chain (lipophilic region), respectively. The electron spin resonance study revealed that Tween 20 increased the fluidity at the C5 atom of the acyl chain, whereas terpenes increased the fluidity at the C16 atom of the acyl chain of the phospholipid bilayer. The increase in liposomal fluidity resulted in the increased skin penetration of sodium fluorescein. Confocal laser scanning microscopy showed that ultradeformable liposomes with terpenes increase the skin penetration of sodium fluorescein by enhancing hair follicle penetration.

Application of Design Expert for the investigation of capsaicin-loaded microemulsions for transdermal delivery

Our previous study reported that the Design Expert® Software showed a beneficial role in the development of microemulsions (ME) for transdermal drug delivery. To fully confirm the reproducibility and the reliability of simultaneous optimal ME formulations, the optimal ME formulations predicted by the Design Expert® Software were experimentally formulated and verified for their skin permeability. Ternary phase diagrams were used to predict the optimal ME area, and the ME formulations selected from outside this area were considered as candidate ME systems. Our ME systems were formulated with isopropyl myristate (IPM) as the oil phase, cocamide diethanolamine (DEA) as the surfactant, ethanol as a co-surfactant and water as the aqueous phase. The droplet size, size distribution, electrical conductivity, pH, drug content and skin permeability of the candidate ME systems were monitored. Our findings indicated that the skin permeability of the optimal ME and all of the candidate ME formulations was significantly greater than that of the commercial capsaicin (CAP) product. Our study succeeded in predicting and developing the ME systems for the transdermal delivery of CAP. The simplex lattice design used in this study is experimentally useful for the development of pharmaceutical formulations.

Mucoadhesive electrospun chitosan-based nanofibre mats for dental caries prevention

The mucoadhesive electrospun nanofibre mats were developed using chitosan (CS) and thiolated chitosan (CS-SH) as mucoadhesive polymers. Garcinia mangostana (GM) extract was incorporated into nanofibre mats. The antibacterial activity in the single and combined agents was evaluated against dental caries pathogens. The morphology of mats was observed using SEM. The mats were evaluated for GM extract amount, mucoadhesion, in vitro release, antibacterial activity and cytotoxicity. The mucoadhesion and antibacterial activity were determined in healthy human volunteers. The prepared mats were in nanoscale with good physical and mucoadhesive properties. The CS-SH caused the higher mucoadhesion. All mats rapidly released active substances, which had the synergistic antibacterial activity. In addition, the reduction of bacteria and good mucoadhesion in the oral cavity occurred without cytotoxicity. The results suggest that mats have the potential to be mucoadhesive dosage forms to maintain oral hygiene by reducing the bacterial growth that causes the dental caries.