Ming-Jun Tsai

Background: Simultaneous anti-Cutibacterium acnes and anti-inflammatory actions are highly beneficial in treating acne vulgaris. In this study, we present novel anti-acne nanovesicles based on liposomes loaded with proteinase K (PK), retinoic acid (RA), and soyaethyl morpholinium ethosulfate (SME) to achieve an effective and safe treatment. Materials and Methods: This study examined in vitro planktonic and biofilm C. acnes elimination, as well as the keratinocyte proliferation suppression by liposomes. The multifunctional liposomes for treating C. acnes in mice were also evaluated. Results: We acquired multifunctional liposomes with a size of 71 nm and zeta potential of 31 mV. The antimicrobial activity of SME was enhanced after liposomal encapsulation according to the reduction of minimum bactericidal concentration (MBC) by 6-fold. The multifunctional liposomes exhibited a synergistically inhibitory effect on biofilm C. acnes colonization compared with the liposomes containing PK or those containing SME individually. The adhesive bacterial colony in the microplate was lessened by 62% after multifunctional liposome intervention. All liposomal formulations tested here demonstrated no cytotoxicity against the normal keratinocytes but inhibited C. acnes-stimulated cell hyperproliferation. The in vitro scratch assay indicated that the liposomal RA—but not free RA—restrained keratinocyte migration. The animal study showed that free RA combined with SME and multifunctional nanovesicles had a similar effect on diminishing C. acnes colonies in the skin. On the other hand, liposomes exhibited superior performance in recovering the impaired skin barrier function than the free control. We also found that RA-loaded nanovesicles had greater skin tolerability than free RA. Conclusion: The cationic liposomes containing dual PK and RA represented a potential treatment to arrest bacterial infection and associated inflammation in acne.

The objective of this study is to design a polymeric network of nanogels for sustained release of caffeine. Therefore, alginate-based nanogels were fabricated by a free-radical polymerization technique for the sustained delivery of caffeine. Polymer alginate was crosslinked with monomer 2-acrylamido-2-methylpropanesulfonic acid by crosslinker N',N'-methylene bisacrylamide. The prepared nanogels were subjected to sol-gel fraction, polymer volume fraction, swelling, drug loading, and drug release studies. A high gel fraction was seen with the increasing feed ratio of polymer, monomer, and crosslinker. Greater swelling and drug release were observed at pH 4.6 and 7.4 as compared to pH 1.2 due to the deprotonation and protonation of functional groups of alginate and 2-acrylamido-2-methylpropanesulfonic acid. An increase was observed in swelling, loading, and release of the drug with the incorporation of a high feed ratio of polymer and monomer, while a reduction was seen with the increase in crosslinker feed ratio. Similarly, an HET-CAM test was used to evaluate the safety of the prepared nanogels, which showed that the prepared nanogels have no toxic effect on the chorioallantoic membrane of fertilized chicken eggs. Similarly, different characterizations techniques such as FTIR, DSC, SEM, and particle size analysis were carried out to determine the development, thermal stability, surface morphology, and particle size of the synthesized nanogels, respectively. Thus, we can conclude that the prepared nanogels can be used as a suitable agent for the sustained release of caffeine.

In this study, we developed polyethylene glycol-4000-based hydrogels for ketorolac tromethamine-controlled delivery systems through a free radical polymerization method. The developed hydrogels were subjected to FTIR, TGA, DSC, XRD, SEM, porosity analysis, dynamic swelling analysis, release studies, etc. The successful crosslinking and stability of the prepared hydrogels were confirmed by FTIR, DSC, and TGA analysis. The surface morphology and the reduction in the crystallinity of the polymer after grafting were shown by SEM and XRD analysis. Similarly, the soluble part of the developed hydrogels was eliminated from their insoluble part by the Soxhlet extraction process. Higher dynamic swelling and drug release were observed at high pH values compared to low pH values. High porosity was perceived with high concentrations of the monomers and polymer and decreased with the high incorporation of a crosslinker. The release mechanism of all formulations followed non-Fickian diffusion. The results demonstrate that the developed polyethylene glycol-4000 hydrogels could serve as promising controlled drug delivery carriers.

Linalool is an aromatic oil with analgesic, anti-inflammatory and anti-UVB-induced skin damage effects. The aim of this study was to develop a linalool-loaded microemulsion formulation for topical application. In order to quickly obtain an optimal drug-loaded formulation, statistical tools of the response surface methodology and a mixed experimental design with four independent variables of oil (X₁), mixed surfactant (X₂), cosurfactant (X₃) and water (X₄) were used to design a series of model formulations in order to analyze the effect of the composition on the characteristics and permeation capacity of linalool-loaded microemulsion formulations and to obtain an appropriate drug-loaded formulation. The results showed that the droplet size, viscosity and penetration capacity of linalool-loaded formulations were significantly affected by formulation component proportions. The skin deposition amount of the drug and flux of such formulations expressively increased about 6.1-fold and 6.5-fold, respectively, when compared to the control group (5% linalool dissolved in ethanol). After 3 months of storage, the physicochemical characteristics and drug level did not show a significant change. The linalool formulation-treated rat skin showed non-significant irritation compared to skin treatments in the distilled-water-treated group. The results showed that specific microemulsion applications might be considered as potential drug delivery carriers for essential oil topical application.

This study investigates pH-sensitive hydrogels based on biocompatible, biodegradable polysaccharides and natural polymers such as chondroitin sulfate and alginate in combination with synthetic monomer such as acrylic acid, as controlled drug carriers. Investigations were conducted for chondroitin sulfate/alginate-graft-poly(acrylic acid) hydrogel in various mixing ratios of chondroitin sulfate, alginate and acrylic acid in the presence of ammonium persulfate and N′,N′-Methylene bisacrylamide. Crosslinking and loading of drug were confirmed by Fourier transform infrared spectroscopy. Thermal stability of both polymers was enhanced after crosslinking as indicated by thermogravimetric analysis and differential scanning calorimeter thermogram of developed hydrogel. Similarly, surface morphology was evaluated by scanning electron microscopy, whereas crystallinity of the polymers and developed hydrogel was investigated by powder X-ray diffraction. Furthermore, swelling and drug-release studies were investigated in acidic and basic medium of pH 1.2 and 7.4 at 37 °C, respectively. Maximum swelling and drug release were detected at pH 7.4 as compared to pH 1.2. Increased incorporation of hydrogel contents led to an increase in porosity, drug loading, and gel fraction while a reduction in sol fraction was seen. The polymer volume fraction was found to be low at pH 7.4 compared to pH 1.2, indicating a prominent and greater swelling of the prepared hydrogels at pH 7.4. Likewise, a biodegradation study revealed a slow degradation rate of the developed hydrogel. Hence, we can conclude from the results that a fabricated system of hydrogel could be used as a suitable carrier for the controlled delivery of ketorolac tromethamine.

Intravesical administration of chemotherapeutic agents can enhance drug accumulation in tumors and reduce systemic side effects. Nanocarriers were developed for intravesical administration and exploit the permeation enhancement effect. In vitro permeation evaluation, the drug transdermal amount and accumulation amounts in the tissue of gemcitabine-loaded nanocarriers through biological membrane significantly increased about 14.8~33.0-fold and 1.5~14.1-fold respectively, when compared to a control group of 1% gemcitabine saline solution. In in vivo intravesical administration, the drug accumulation amount in bladder tissue of nanocarrier of 75.2 ± 5.4 μg was revealed as being comparably higher than that of the control group of 44.8 ± 6.4 μg. In confocal laser scanning microscopy imagery, the penetration depth of fluorescent dyes-rhodamine was increased from 80 μm up to 120 μm when a nanocarrier was used. This result implies that the nanocarrier is a promising drug delivery agent for intravesical administration.

Combined chemotherapy is an effective and safe treatment for cancers. Co-administration of cisplatin and gemcitabine produces a synergistic effect for bladder cancer treatment, so viscous microemulsions were developed for co-delivery of cisplatin and gemcitabine to extend the retention time and improve the permeability of chemotherapeutic drugs into the urothelium by intravesical administration. Results showed that the deposition amounts of cisplatin and gemcitabine significantly increased in in vitro and in vivo study. The penetration depth in bladder tissue samples increased from 60 to 120 μm. The dual-loaded formulation also showed thermodynamic and chemical stability, demonstrating that these gel-based microemulsions are promising drug delivery carriers for chemotherapy agents by intravesical administration.

A combination of long-acting anticholinergic agents (LAACs) and long-acting β2-adrenergic receptor agonist (LABA) is effective in improving lung function in chronic obstructive pulmonary disease (COPD) compared with monotherapy. However, evidence on whether this combination increases the incidence of stroke or other cardiac events remains sparse. The objective of the present study was to investigate the incidence of stroke and other cardiovascular diseases in COPD patients treated with LAAC, LABA, or a combination of the 2.We conducted this population-based study using the Taiwan National Health Insurance Research Database (1997-2008), identifying COPD patients and their prescribed medication from the International Classification of Disease, Ninth Revision codes 490-492 or 496. A multivariate Cox proportional-hazards model was used to compare the risk of stroke and other cardiovascular diseases over the 11-year period after treatment with LAAC or LABA only or in combination.Of the 596 COPD patients (mean age 70 y), 196 were treated with LAAC, 318 with LABA, and 82 were treated with a combination. The overall incidence of stroke (8.53%) significantly increased in the combination group compared with LAAC (2.04%) or LABA (1.26%) only. In the Cox regression analysis, the adjusted hazard ratio over the 11-year survey period for stroke in patients treated with the combination compared with LABA only was 1.04 (95% confidence interval, 1.06-2.99) and for LAAC, it was 0.31 (95% confidence interval, 0.02-2.32).This cohort study using a large health insurance database showed that treating patients with COPD, with a combination of LAAC and LABA, may be associated with an increased hazard of stroke compared with treatment with either agent alone. We should be particularly cautious about comedication of LAAC and LABA in patients with COPD.