ABSTRACT
OBJECTIVE@#Hypertrophic scars (HS) are a variety of skin tissue fibrosis disease that occurs in human skin, the effective therapeutic method of which is still inaccessible up to now. As a bioactive constituent of a well-known medical plant, Salvia miltiorrhiza (Danshen in Chinese), tanshinone IIA (TSA) is reported to inhibit cell proliferation in HS. Therefore, the aim of this study was to prepare TSA self-soluble microneedles to strengthen its dermal retention and break through the difficulty of significantly thickening epidermal connective tissue and stratum corneum at the HS site. The possible mechanism of action in suppressing HS was studied using human skin fibroblasts (HSF).@*METHODS@#Tanshinone IIA self-dissolving microneedles (TSA-MN) was prepared using a negative mold casting method. The prescription process of microneedle was optimized by Box-Behnken effect surface method. Different media were selected to investigate the ability of transdermal absorption and in vitro release. Furthermore, according to Cell Counting Kit-8 (CCK8) method as well as the Western blot method, the effect of TSA-MN on the biological characteristics of HSF was investigated.@*RESULTS@#With remarkable slow release effect and dermal retention, the release and transdermal properties of TSA-MN in vitro were better than both TSA and ordinary dosage forms. Its effect of HSF confirmed the essential decrease in cell motility during cell proliferation and cell migration in vitro, which plays a significant role in down-regulating the secretion of transforming growth factor-β1 (TGF-β1) in HSF and increasing the expression level of Smad7.@*CONCLUSION@#The prepared TSA self-soluble microneedles is helpful in solving the problem of hypertrophic scars, with a stable dermal retention effect after process optimization.
ABSTRACT
Triptolide(TP), the main active and toxic component of Tripterygium wilfordii, has the limitations of low bioavailability, poor absorption, low concentration in plasma, and small lethal dose. Microneedle(MN), the hybrid of hypodermic needle and transdermal patch, is a physical penetration-enhancing system. Dissolving microneedles(DMNs) can be tailored to specific needs of degradation rate. In this study, the TP-loaded DMNs(DMNs-TP) were prepared with the two-step centrifugation method. The optimal ratio of PVA to PVP K30, water content in matrix solution, demoulding method, and plasticizer for preparing DMNs were investigated with the indexes of formability and mechanical strength. The drug loading capacity was determined by HPLC and morphological characteristics were observed under an optical microscope. The mechanical properties were investigated by H&E staining and Franz diffusion cell was used to detect the in vitro skin permeation characteristics. Through the experiment, we confirmed that the optimal backing material should be PVA and PVP K30(3∶1) and the optimal ratio of matrix material to water should be 3∶4. The prepared DMNs-TP were pyramidal with smooth surface and length of approximately 550 μm. Each patch(2.75 cm~2) had the drug loading capacity of(153.41±2.29) μg, and TP was located in the upper part of the needle. The results of in vitro skin permeation assay demonstrated that the cumulative penetration of TP in DMNs-TP reached 80% in 24 h, while little TP solution penetrated the skin, which proved that DMNs promoted the transdermal delivery of TP.
Subject(s)
Administration, Cutaneous , Diterpenes , Drug Delivery Systems , Epoxy Compounds , Needles , Phenanthrenes , SkinABSTRACT
Nanoparticles (NPs) have shown potential in cancer therapy, while a single administration conferring a satisfactory outcome is still unavailable. To address this issue, the dissolving microneedles (DMNs) were developed to locally deliver functionalized NPs with combined chemotherapy and photothermal therapy (PTT).
ABSTRACT
Objective: To prepare Naja atra neurotoxin (NT) loaded dissolving microneedles (DMNs-NT), and investigate the physicochemical properties and in vitro transdermal properties. Methods: DMNs-NT was prepared by a two-step centrifugation method. The ratio of CS and PVP K30, the water content of the matrix solution, and the backing layer material were optimized by the indexes of formability and mechanical strength of the microneedles and flexibility of the backing layer. The drug loading content was determined by HPLC, and the morphological characteristics were observed under an optical microscope, and the stability was also examined. Franz diffusion cell was used to investigate its in vitro skin permeation characteristics. Results: Through the single-factor exploration, we confirmed that the optimal prescription technique for DMNs-NT preparation was a 1:1 ratio of CS and PVP k30, a 5:4 ratio of matrix material and water, with CMC as the backing layer material. The DMNs-NT had a pyramidal shape with a smooth surface and a length of approximately 500 μm. The drug loading content of per tablet was (15.4 ± 0.5) μg. The drug was located in the upper part of the needle. DMNs-NT had good stability within 3 months. The results of in vitro skin permeation assay showed that the cumulative penetration of NT in DMNs-NT could reach 95.8% in 4 h, while NT solution barely penetrated the skin, which proved that it had a good promoting effect on NT transdermal delivery. Conclusion: In this study, DMNs-NT had good mechanical properties and good skin penetration, which realized the transdermal drug delivery of macromolecular drugs.
ABSTRACT
OBJECTIVE: To optimize the formulation and preparation process of fast-dissolving PVP microneedles, and provide a high-quality carrier for PVP drug-loaded microneedle research. METHODS: On the basis of single factor, the needle tips dissolution time and insertion ratio were used as the evaluation indexes, and the optimal preparation process of microneedle was optimized by Box-Behnken method. RESULTS: From the single factor test and the Box-Behnken test, it was known that the optimum preparation conditions were as follows: the needle tip concentration was 0.70 g•mL-1, the temperature was 40 ℃, and the humidity was 40%. The microneedle height was 600 μm, the width was 200 μm, the pitch was 500 μm, quadrangular pyramid. The area of the microneedle patch was 0.56 cm2, the dissolution time in water was (41.00±3.74)s, and the insertion ratio was (93.19±5.25)%. CONCLUSION: The PVP fast-dissolving microneedles can be prepared simply and conveniently by the Box-Behnken method, which provides a reference for the preparation of further drug-loaded microneedles.
ABSTRACT
Dissolving microneedles carried drug molecules can effectively penetrate the stratum corneum of skin to improve the transdermal drug delivery. The traditional Chinese medicine acupuncture is based on the needle stimulation at a specific location (acupoint) to generate and transmit biochemical and physiological signals which alter the pathophysiological state of patients. However, the pain associated with conventional acupuncture needles and the requirement of highly trained professionals limit the development of acupuncture in non-Asian countries. The purpose of this study is to investigate whether the dissolving microneedles can be utilized as a self-administered painless replacement for acupuncture and locally released drug molecules can achieve expected therapeutic outcomes. Immunosuppressive rats were treated with acupuncture at Zusanli (ST36) acupoint using microneedles containing thymopentin. The immune functions and psychological mood of the immunosuppressed animals were examined. The proliferation of splenocytes was examined by CCK-8 assay. CD4 and CD8 expression patterns in spleen cells were detected by flow cytometry. The current study showed that use of either microneedles containing thymopentin or conventional acupuncture both resulted in immune cell proliferation, which was confirmed by flow cytometry. Furthermore, either conventional acupuncture or microneedles were able to effectively mitigate the anxiety caused by immune-suppression when applied on the ST36.