Industrializable approach for preparing hydrogel microneedles and their application in melanoma treatment.

Microneedles (MNs) technology has been studied in transdermal drug delivery for more than 20 years with hundreds of clinical trials conducted. However, there are currently no commercially available MNs in medicine due to challenges in materials safety, cost-effective fabrication, and large-scale manufacturing. Herein, an approach for rapid and green fabrication of hydrogel microneedles (HMNs) based on infrared irradiation process was proposed for the first time. The optimized formulation consisted of polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP), which acted as cross-linked materials and pore-forming agents, respectively. The manufacturing method involved placing MNs patches under infrared irradiation at 70 °C for 2 min and annealing to obtain HMNs with excellent swelling behavior, mechanical strength, and biocompatibility. When model drugs azelaic acid (AZA) and matrine (MAT) were loaded into HMNs systems, the chemical stability of MAT was significantly improved. Ex vivo transdermal delivery experiments indicated that HMNs could achieve synchronous release of AZA and MAT, and the 24-hour percutaneous permeability rates of both drugs were 73.09 ± 0.48 % and 71.56 ± 1.23 %, respectively. In-vivo pharmacokinetic studies, HMNs administration presented dose-dependent stable blood drug concentrations for both drugs. Additionally, prominent anti-tumor efficacy and biosecurity were observed in the drug-loaded HMNs group in the pharmacodynamic evaluation. In summary, the efficient, convenient, and low-cost fabrication method based on infrared irradiation offers the possibility of mass production of drug-loaded HMNs, showing potential for industrial manufacturing development.

Dissolvable polymeric microneedles loaded with aspirin for antiplatelet aggregation.

To reduce mucosal damage in the gastrointestinal tract caused by aspirin, we developed a dissolvable polymeric microneedle (MN) patch loaded with aspirin. Biodegradable polymers provide mechanical strength to the MNs. The MN tips punctured the cuticle of the skin and dissolved when in contact with the subcutaneous tissue. The aspirin in the MN patch is delivered continuously through an array of micropores created by the punctures, providing a stable plasma concentration of aspirin. The factors affecting the stability of aspirin during MNs fabrication were comprehensively analyzed, and the hydrolysis rate of aspirin in the MNs was less than 2%. Compared to oral administration, MN administration not only had a smoother plasma concentration curve but also resulted in a lower effective dose of antiplatelet aggregation. Aspirin-loaded MNs were mildly irritating to the skin, causing only slight erythema on the skin and recovery within 24 h. In summary, aspirin-loaded MNs provide a new method to reduce gastrointestinal adverse effects in patients requiring aspirin regularly.

Two-Layer Sustained-Release Microneedles Encapsulating Exenatide for Type 2 Diabetes Treatment.

Daily administration of multiple injections can cause inconvenience and reduce compliance in diabetic patients; thus, microneedle (MN) administration is favored due to its various advantages. Accordingly, the two-layer sustained-release MNs (TS-MNs) were fabricated by encapsulating exenatide (EXT) in calcium alginate (CA) gel in this work. The TS-MNs were composed of a sodium alginate (SA) tip and a water-soluble matrix-containing calcium chloride (CaCl2). Subsequently, the calcium ion (Ca2+) contained in the matrix layer penetrated the tip layer for cross-linking, leaving the drug in the cross-linked network. The patches have adequate mechanical strength to pierce the skin; then, the matrix layer is dissolved, leaving the tip layer to achieve sustained release. Additionally, the TS-MNs encapsulating EXT retained high activity during long-term storage at room temperature. The pharmacokinetic results indicated that the plasma concentrations of EXT were sustained for 48 h in the EXT MN group, which agreed with the in vitro release test. Furthermore, they had high relative bioavailability (83.04%). Moreover, the hypoglycemic effect was observed to last for approximately 24 h after a single administration and remained effective after multiple administrations without drug resistance. These results suggest that the TS-MNs are a promising depot for the sustained delivery of encapsulated EXT.

Process optimization of Ca2+ cross-linked alginate-based swellable microneedles for enhanced transdermal permeability: More applicable to acidic drugs.

We describe a swellable microneedle (SMN) consisting of Ca2+ cross-linked alginate, which expands the types of natural polymers available for SMN fabrication. After investigation of different fabrication methods, the alginate in situ hydrogel-based SMN with a flat substrate was successfully constructed, whose gelation was triggered by ethylenediaminetetraacetic acid calcium disodium salt and D-(+)-glucono-1,5-lactone. With the addition of polyvinyl alcohol and trehalose, SMN possessed good mechanical properties. The biocompatibility of SMN was demonstrated through the tests of in vitro cytotoxicity and in vivo skin irritation. With the assistance of SMN, the in vitro transdermal delivery efficiencies of drugs were significantly improved throughout 16 h. 3-O-ethyl ascorbic acid (EAA, pH = 4.81) exhibited a cumulative release of up to 83.83 ± 6.30%, which was consistent with zero-order kinetics, while tranexamic acid (TA, pH = 6.90) showed the most significant increase in delivery efficiency, which was consistent with the Higuchi model and Ritger-Peppas model. The SMN remained intact after the 16 h of EAA transdermal delivery, indicating its better suitability for acidic drugs. We believe that this technology has the potential to expand the range of drugs available for transdermal administration as well as the breadth of patient care applications.

Enhanced delivery efficiency and sustained release of biopharmaceuticals by complexation-based gel encapsulated coated microneedles: rhIFNα-1b example.

Coated microneedles (MNs) are widely used for delivering biopharmaceuticals. In this study, a novel gel encapsulated coated MNs (GEC-MNs) was developed. The water-soluble drug coating was encapsulated with sodium alginate (SA) in situ complexation gel. The manufacturing process of GEC-MNs was optimized for mass production. Compared to the water-soluble coated MNs (72.02% ± 11.49%), the drug delivery efficiency of the optimized GEC-MNs (88.42% ± 6.72%) was steadily increased, and this improvement was investigated through in vitro drug release. The sustained-release of BSA was observed in vitro permeation through the skin. The rhIFNα-1b GEC-MNs was confirmed to achieve biosafety and 6-month storage stability. Pharmacokinetics of rhIFNα-1b in GEC-MNs showed a linearly dose-dependent relationship. The AUC of rhIFNα-1b in GEC-MNs (4.51 ng/ml·h) was bioequivalent to the intradermal (ID) injection (5.36 ng/ml·h) and significantly higher than water-soluble coated MNs (3.12 ng/ml·h). The rhIFNα-1b elimination half-life of GEC-MNs, soluble coated MNs, and ID injection was 18.16, 1.44, and 2.53 h, respectively. The complexation-based GEC-MNs have proved to be more efficient, stable, and achieve the sustained-release of water-soluble drug in coating MNs, constituting a high value to biopharmaceutical.

Novel dissolving microneedles preparation for synergistic melasma therapy: Combined effects of tranexamic acid and licorice extract.

The aim of this study was to prepare dissolving microneedles (DMNs) patches containing tranexamic acid (TA) for the treatment of melasma. Polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) were preferred as matrix materials through the compatibility experiment. In the in vitro permeation study, the transdermal amount of TA was significantly promoted through dissolving microneedles with the cumulative release was 44.43 ± 6.55%. By comparison, the release of TA solution assisted with solid microneedles (SMNs) was merely 11.31 ± 2.30% (p < 0.05). Pharmacokinetics study indicated the bioavailability of dissolving microneedles was more than 1.3 times compared with oral administration. In pharmacodynamics investigation, TA dissolving microneedles obviously reduced melanin deposition in the skin of melasma guinea pigs after 8 consecutive administrations. In particular, the combination of tranexamic acid and licorice extract (LIC) dissolving microneedles worked better than tranexamic acid alone. Accelerated stress conditions including high temperature, high humidity, as well as photostability were designed to prove that TA microneedles maintained good pharmaceutical stability. In conclusion, tranexamic acid dissolving microneedles showed reliable quality and remarkable effect. Moreover, the combination of tranexamic acid and licorice extract had a synergistic therapy in melasma.

Exploring Trehalose on the Release of Levonorgestrel from Implantable PLGA Microneedles.

Hydrophobic drugs wrapped in poly (lactic-co-glycolic acid) (PLGA)-based microneedles (MNs) require a long time to release completely. To obtain the desired duration, it is still necessary to modulate the release of hydrophobic drugs from MNs, while the PLGA composition is unchangeable. In this work, implantable PLGA microneedles (IPMNs) composed of PLGA arrowheads encapsulating levonorgestrel (LNG) and a water-soluble supporting array were designed. We explored trehalose used as a porogen on the release of hydrophobic LNG from PLGA-based MNs. Varying the trehalose content in PLGA arrowheads could induce different rates of drug release. The highest cumulative release of LNG was 76.2 ± 3.9% for IPMNs with 33.3% trehalose during 21 days in vitro, while the cumulative release of LNG was 60.4 ± 3.5% for IPMNs without trehalose. Pharmacokinetic results in rats showed that plasma levels of LNG were sustained for 13 days for IPMNs with 33.3% trehalose and 16 days for IPMNs without trehalose. Furthermore, the PLGA arrowheads with trehalose degraded more rapidly than those without trehalose over 21 days in rats. Consequently, using trehalose as a porogen was a feasible approach to modulate the release of a hydrophobic drug from PLGA-based MNs.

Retraction Note to: SOX2 oncogenes amplified and operate to activate AKT signalling in gastric cancer and predict immunotherapy responsiveness.

The Editor-in-Chief is retracting this article (Tian et al 2014) due to concerns regarding peer review, authorship and originality of the article.

A Novel Coumarin-Based Fluorescent Probe for the Detection of Hydrazine Both in Aqueous Solution and Vapor State.

A novel coumarin-based fluorescent probe CF was synthesized for the detection of hydrazine both in aqueous solution and vapor state with high sensitivity and selectivity. Upon addition of hydrazine, the solution of probe CF in MeCN-H2O (3/7, v/v, buffered CH3COOH/CH3COONa) at pH 5.0 exhibited a remarkable change in emission color from pale green to light blue, which could be recognized with naked eyes. Applied in weak acid condition, probe CF could detect hydrazine selectively with large amount of unknown environments according to the competing tests. Besides, with the limit of detection 8.32 ppb (2.6 × 10(-7) M), probe CF could well meet the request (10 ppb) of the U.S. Environmental Protection Agency (EPA).

A dansyl based fluorescence chemosensor for Hg(2+) and its application in the complicated environment samples.

We have developed a novel fluorescent chemosensor (DAM) based on dansyl and morpholine units for the detection of mercury ion with excellent selectivity and sensitivity. In the presence of Hg(2+) in a mixture solution of HEPES buffer (pH 7.5, 20 mM) and MeCN (2/8, v/v) at room temperature, the fluorescence of DAM was almost completely quenched from green to colorless with fast response time. Moreover, DAM also showed its excellent anti-interference capability even in the presence of large amount of interfering ions. It is worth noting that DAM could be used to detect Hg(2+) specifically in the Yellow River samples, which significantly implied the potential applications of DAM in the complicated environment samples.

Apoptotic effect of genistein on human colon cancer cells via inhibiting the nuclear factor-kappa B (NF-κB) pathway.

Genistein possesses a wide variety of biological activities, and it is best known for its ability to inhibit cancer progression. Its cancer-preventive effect has been attributed to various mechanisms, including the induction of cell cycle arrest and apoptosis as well as the antioxidant functions. Nuclear factor kappa-B (NF-κB) is a signaling pathway that controls transcriptional activation of genes important for the tight regulation of many cellular processes and is aberrantly expressed in many types of cancer. Inhibitors of NF-κB pathway have shown potential anti-tumor activities. However, it is not fully elucidated in colon cancer. In the present study, we demonstrated that genistein could induce apoptosis in human colon cancer LoVo and HT-29 cells through inhibiting NF-κB pathway, as well as downregulation of Bcl-2 and upregulation of Bax, thus providing basis for clinical application of genistein in colon cancer cases.

Quercetin induces HepG2 cell apoptosis by inhibiting fatty acid biosynthesis.

Quercetin can inhibit the growth of cancer cells with the ability to act as a 'chemopreventer'. Its cancer-preventive effect has been attributed to various mechanisms, including the induction of cell-cycle arrest and/or apoptosis, as well as its antioxidant functions. Quercetin can also reduce adipogenesis. Previous studies have shown that quercetin has potent inhibitory effects on animal fatty acid synthase (FASN). In the present study, activity of quercetin was evaluated in human liver cancer HepG2 cells. Intracellular FASN activity was calculated by measuring the absorption of NADPH via a spectrophotometer. MTT assay was used to test the cell viability, immunoblot analysis was performed to detect FASN expression levels and the apoptotic effect was detected by Hoechst 33258 staining. In the present study, it was found that quercetin could induce apoptosis in human liver cancer HepG2 cells with overexpression of FASN. This apoptosis was accompanied by the reduction of intracellular FASN activity and could be rescued by 25 or 50 µM exogenous palmitic acids, the final product of FASN-catalyzed synthesis. These results suggested that the apoptosis induced by quercetin was via the inhibition of FASN. These findings suggested that quercetin may be useful for preventing human liver cancer.

SOX2 oncogenes amplified and operate to activate AKT signaling in gastric cancer and predict immunotherapy responsiveness.

INTRODUCTION: Gastric cancer is the second leading cause of cancer mortality in the world. Whether the oncogene, amplified on chromosome 3q26, SOX2, a master transcriptional regulator of stemness, operate to drive strong growth phenotype in gastric cancer were unknown. MATERIALS AND METHODS: The gene expression changes of SOX2 in human gastric cancer tissues compared with non-cancerous tissues was detected using real-time quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR) analysis and immunohistochemistry, which identified the gene overexpression of SOX2 in gastric cancer. Moreover, we discovered that SOX2 promoted cancer cell proliferation in vitro/vivo and SOX2 expression correlated with elevated AKT phosphorylation in gastric cancer, while the AKT phosphorylation was required for SOX2's oncogenic effects. Next, our data point to the usefulness of SOX2 overexpression, as a new predictive marker for responsiveness to trastuzumab. CONCLUSION: SOX2 is a commonly activated tumor promoter that activate AKT signaling in gastric cancer and a new predictive marker for targeted therapy.

A unique dansyl-based chromogenic chemosensor for rapid and ultrasensitive hydrazine detection.

We developed a new dansyl phthalimide-based fluorescent chemosensor for hydrazine detection. Upon a Gabriel type-based hydrazinolysis of dansyl phthalimide (DPI) in the presence of hydrazine in a mixture of HEPES buffer (pH 7.0, 20 mM) and DMSO (1/9, v/v) at room temperature, the chemosensor produces fluorescent dansyl-NH2 with the maximum emission wavelength changed from 475 nm to 512 nm along with a color change from yellow to colorless, allowing colorimetric detection of hydrazine by the naked eye. DPI can selectively detect hydrazine over other environmentally abundant ions. Moreover, DPI coated with silica gel TLC plates could act as a visual and fluorimetric probe for hydrazine vapor at a partial pressure of 5.5 × 10-3 mm Hg over other potentially interfering volatile analytes, including hydrogen peroxide, ethylenediamine, urea, ammonium hydroxide and methylamine. DPI can also be used for the detection of hydrazine in water samples and HeLa cells without appreciable interference from other biologically abundant analytes. The limit of detection is 6.01 ppb (1.88 × 10-7 M), which is well below the accepted limit (10 ppb) for hydrazine set by the U.S. Environmental Protection Agency (EPA).