Mechanisms of Penetration Enhancement and Transport Utilizing Skin Keratine Liposomes for the Topical Delivery of Licochalcone A.

Keratin liposomes have emerged as a useful topical drug delivery system given theirenhanced ability to penetrate the skin, making them ideal as topical drug vehicles. However, the mechanisms of the drug penetration enhancement of keratin liposomes have not been clearly elucidated. Therefore, licochalcone A(LA)-loaded skin keratin liposomes (LALs) were prepared to investigate their mechanisms of penetration enhancement on the skin and inB16F10 cells. Skin deposition studies, differential scanning calorimetry (DSC), attenuated total reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR), and skin distribution and intracellular distribution studies were carried out to demonstrate the drug enhancement mechanisms of LALs. We found that the optimal application of LALs enhanced drug permeation via alterations in the components, structure, and thermodynamic properties of the stratum corneum (SC), that is, by enhancing the lipid fluidization, altering the skin keratin, and changing the thermodynamic properties of the SC. Moreover, hair follicles were the main penetration pathways for the LA delivery, which occurred in a time-dependent manner. In the B16F10 cells, the skin keratin liposomes effectively delivered LA into the cytoplasm without cytotoxicity. Thus, LAL nanoparticles are promising topical drug delivery systems for pharmaceutical and cosmetic applications.

Formulation and Characterization of a 3D-Printed Cryptotanshinone-Loaded Niosomal Hydrogel for Topical Therapy of Acne.

Cryptotanshinone (CPT) is an efficacious acne treatment, while niosomal hydrogel is a known effective topical drug delivery system that produces a minimal amount of irritation. Three-dimensional (3D) printing technologies have the potential to improve the field of personalized acne treatment. Therefore, this study endeavored to develop a 3D-printed niosomal hydrogel (3DP-NH) containing CPT as a topical delivery system for acne therapy. Specifically, CPT-loaded niosomes were prepared using a reverse phase evaporation method, and the formulation was optimized using a response surface methodology. In vitro characterization showed that optimized CPT-loaded niosomes were below 150 nm in size with an entrapment efficiency of between 67 and 71%. The CPT-loaded niosomes were added in a dropwise manner into the hydrogel to formulate CPT-loaded niosomal hydrogel (CPT-NH), which was then printed as 3DP-CPT-NH with specific drug dose, shape, and size using an extrusion-based 3D printer. The in vitro release behavior of 3DP-CPT-NH was found to follow the Korsmeyer-Peppas model. Permeation and deposition experiments showed significantly higher rates of transdermal flux, Q24, and CPT deposition (p < 0.05) compared with 3D-printed CPT-loaded conventional hydrogel (3DP-CPT-CH), which did not contain niosomes. In vivo anti-acne activity evaluated through an acne rat model revealed that 3DP-CPT-NH exhibited a greater anti-acne effect with no skin irritation. Enhanced skin hydration, wide inter-corneocyte gaps in the stratum corneum and a disturbed lipid arrangement may contribute towards the enhanced penetration properties of CPT. Collectively, this study demonstrated that 3DP-CPT-NH is a promising topical drug delivery system for personalized acne treatments.

In Situ Polymerization Approach to Graphene-Oxide-Reinforced Silicone Composites for Superior Anticorrosive Coating.

Novel graphene-oxide-reinforced silicone composites (GOSC) are prepared by in situ polymerization of silanes and low concentrations (<0.15 wt%) of silylated GO (SGO). After modification, the distances of the SGO nanosheets are successfully increased from 0.72 to 0.87 nm. Compared with GO, the SGO shows better dispersibility in organic solvents as well as remarkably enhanced decomposition temperature (T d improved by 100 °C). After covalently grafting onto silicone resins via in situ polymerization, the obtained GOSC exhibits greatly enhanced thermal stability (T d up to 400 °C and T g improved by 3-5 °C), increased storage modulus, loss modulus, and complex viscosity. The morphology, microstructure, interfacial adhesion of the developed GOSC coatings were carefully investigated. The GOSC coatings on metal exhibit good transparency (up to 90%), hydrophobicity, and excellent anticorrosion capability. This work provides a new strategy for developing high performance graphene-based silicone composite materials.

Synthesis of ractopamine molecularly imprinted membrane and its application in the rapid determination of three ß-agonists in porcine urine samples.

A novel molecularly imprinted membrane (MIM) with ractopamine (RAC) as the template and the hydrophilic PVDF membrane as the support was synthesized for the selective absorption of RAC and its structure analogues. The absorption behavior and selectivity of the MIM were studied. The experimental results showed that the MIM had the good selectivity to three ß-agonists including RAC, RIT, and formoterol (FOM) than that of nonimprinted membrane. The adsorption capacity for three compounds was above 1.88 µg/cm(2) of per membrane. Based on the clean-up and enrichment of porcine urine samples with the MIM, a sensitive determination method of three ß-agonists in porcine urine samples by using MIM followed ultra performance chromatography coupled MS/MS detection was developed. The LOD and LOQ for RAC, RIT, and FOM were below 0.006 and 0.02 ng/mL, respectively. The mean recoveries, repeatability, and reproducibility of three compounds in porcine urine samples varied from 67.9 to 86.3%, from 3.3 to 10.8%, and from 5.3 to 8.5%, respectively. The presented method was applied to test 50 real porcine urine samples. It was demonstrated to be more sensitive and robust for the determination of RAC, RIT, and FOM in porcine urine.

Development of kartogenin-conjugated chitosan-hyaluronic acid hydrogel for nucleus pulposus regeneration.

Injectable constructs for in vivo gelation have many advantages in the regeneration of degenerated nucleus pulposus. In this study, an injectable hydrogel consisting of chitosan (CS) and hyaluronic acid (HA) crosslinked with glycerol phosphate (GP) at different proportions (CS : GP : HA, 6 : 3 : 1, 5 : 3 : 2, 4 : 3 : 3, 3 : 3 : 4, 2 : 3 : 5, 1 : 3 : 6, V : V : V) was developed and employed as a delivery system for kartogenin (KGN), a biocompound that can activate chondrocytes. In vitro gelation time, morphologies, swelling, weight loss, compressive modulus and cumulative release of KGN in hydrogels were studied. For biocompatibility assessments, human adipose-derived stem cells (ADSCs) were encapsulated in these hydrogels. The effects of KGN on stem cell proliferation and differentiation into nucleus pulposus-like cells were examined. The hydrogels with higher concentrations of HA showed a slightly shorter gelation time, higher water uptake, faster weight loss and faster KGN release compared to the hydrogels with lower concentrations of HA. As the KGN-conjugated hydrogel prepared with the proportions 5 : 3 : 2 displayed good mechanical properties, it was chosen as the optimal gel to promote cell proliferation and differentiation. No significant difference was seen in the expression levels of nucleus pulposus markers induced by KGN or TGF-ß. Additionally, inclusion of KGN and TGF-ß together did not produce a synergistic effect in inducing nucleus pulposus properties. In conclusion, we have developed a KGN-conjugated CS/HA hydrogel (5 : 3 : 2) with sustained release of KGN in hydrogel that can promote ADSC proliferation and nucleus pulposus differentiation. This kind of hydrogel may be a simple and effective candidate for the repair of degenerative NP tissue after minimally invasive surgery.