Astragalus membranaceus(Fisch.)Bge.administered by dissolving microneedles achieves systemic therapeutic effects at low doses Author links open overlay panel

Objective:To determine the main components of Astragalus membranaceus(Fisch.)Bge(A.membranaceus,Huang Qi),Astragaloside IV(AIV)and Astragalus polysaccharides(AP),to characterize their properties,evaluate their in vivo efficacy,and to analyze drug diffusion using dissolving microneedle(DMN)technology in vivo.Methods: Respectively,AIV-and AP-loaded DMNs comprising chitosan(CTS)and polyvinyl alcohol(PVA)were prepared via dual-mold forming.Their morphology,mechanical properties,in vivo solubility,and skin irritation characteristics were tested.In vivo efficacy was assessed in cyclophosphamide-induced immunosuppressed mice,in vivo diffusion of AIV and AP by DMNs and conventional methods was compared,and the rheological properties of AIV-CTS-PVA and AP-CTS-PVA mixtures were measured.Results: Subcutaneous dissolution and absorption of AIV-CTS-PVA and AP-CTS-PVA microneedles(MNs)at low doses(50%–17%of intraperitoneal AIV injection and 12%–4%of intravenous AP injection)reduced the spleen index and acid phosphatase activity in immunosuppressed mouse models,increased the thymus index,and achieved equivalent or better systemic therapeutic effects.Compared with injections,AIV and AP achieved controllable solid-liquid conversion through delivery with CTS-PVA MNs,resulting in highly localized aggregation within 48 h,reducing the initial explosive effect of the drug,and achieving stable and slow drug release.Conclusion: The present study enhances our understanding of the efficacy and remote effects of drug-loaded DMNs from a traditional Chinese medicine(TCM)perspective,thereby promoting the development of precise and efficient delivery of TCM and further expanding the drug-loading range and application scenarios for DMNs.

Development, Application and Prospect of Dissolving Microneedles

In recent years, as a new transdermal drug delivery method, microneedle transdermal drug delivery technology accelerates the absorption of drugs through micron pores, which has been widely used in the field of medicine and cosmetics. Dissolving microneedles have the characteristics of good biocompatibility and fast dissolution speed, which attract more and more researchers’ attention and research. In this paper, the concept, properties and preparation methods of dissolving microneedles as well as the research status of dissolving microneedles in the field of medicine and cosmetics in recent years were summarized and prospected, so as to enable researchers to have a clearer and comprehensive understanding of dissolving microneedles and prospect the application and development prospects of dissolving microneedles in the industry.

pH-activatable oxidative stress amplifying dissolving microneedles for combined chemo-photodynamic therapy of melanoma

Photodynamic therapy(PDT)-mediated oxidation treatment is extremely attractive for skin melanoma ablation,but the strong hydrophobicity and poor tumor selectivity of photosensitizers,as well as the oxygen-consuming properties of PDT,leading to unsatisfactory therapeutic outcomes.Herein,a tumor acidic microenvironment activatable dissolving microneedle(DHA@HPFe-MN)was developed to realize controlled drug release and excellent chemo-photodynamic therapy of melanoma via oxidative stress amplification.The versatile DHA@HPFe-MN was fabricated by crosslinking a self-synthesized protoporphyrin(PpIX)-ADH-hyaluronic acid(HA)conjugate HA-ADH-PpIX with“iron reservoir”PA-Fe 3+complex in the needle tip via acylhydrazone bond formation,and dihydroartemisinin(DHA)was concurrently loaded in the hydrogel network.HA-ADH-PpIX with improved water solubility averted undesired aggregation of PpIX to ensure enhanced PDT effect.DHA@HPFe-MN with sharp needle tip,efficient drug loading and excellent mechanical strength could efficiently inserted into skin and reach the melanoma sites,where the acidic pH triggered the degradation of microneedles,enabling Fe-activated and DHA-mediated oxidation treatment,as evidenced by abundant reactive oxygen species(ROS)generation.Moreover,under light irradiation,a combined chemo-photodynamic therapeutic effect was achieved with amplified ROS generation.Importantly,the Fe-catalyzed ROS production of DHA was oxygen-independent,which work in synergy with the oxygen-dependent PDT to effectively destroy tumor cells.This versatile microneedles with excellent biosafety and biodegradability can be customized as a promising localized drug delivery system for combined chemo-photodynamic therapy of melanoma.

Synergistic immunoreaction of acupuncture-like dissolving microneedles containing thymopentin at acupoints in immune-suppressed rats

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.

TPGS/hyaluronic acid dual-functionalized PLGA nanoparticles delivered through dissolving microneedles for markedly improved chemo-photothermal combined therapy of superficial tumor

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).α-Tocopheryl polyethylene glycol succinate(TPGS)/hyaluronic acid(HA)dualfunctionalized PLGA NPs(HD10 NPs)were fabricated to co-load paclitaxel and indocyanine green.HD10 NPs significantly enhanced the cytotoxicity of low-dose paclitaxel because of active and mitochondrial targeting by HA and TPGS,respectively.PTT could further sensitize tumor cells toward chemotherapy by promoting apoptosis into the advanced period,highly activating caspase 3 enzyme,and significantly reducing the expression of survivin and MMP-9 proteins.Further,the anti-tumor effects of HD10 NPs delivered through different administration routes were conducted on the 4 T1 tumorbearing mice.After a single administration,HD10 NPs delivered with DMNs showed the best antitumor effect when giving chemotherapy alone.As expected,the anti-tumor effect was profoundly enhanced after combined therapy,and complete tumor ablation was achieved in the mice treated with DMNs and intra-tumor injection.Moreover,DMNs showed better safety due to moderate hyperthermia.Therefore,the DMNs along with combined chemo-photothermal therapy provide a viable treatment option for superficial tumors.

Multidrug dissolvable microneedle patch for the treatment of recurrent oral ulcer

Recurrent oral ulcer is a painful oral mucosal disorder that affects 20%of the world’s population.The lack of a radical cure due to its unknown underlying cause calls for innovative symptomatic treatments.This work reports a hyaluronic acid-based dissolvablemicroneedle patch(ROUMNpatch,short for recurrent oral ulcer microneedle)loaded with dexamethasone acetate,vitamin C and tetracaine hydrochloride for the treatment of recurrent oral ulcers.The ROUMN patch shows enhancement in both the anti-inflammatory effect elicited by dexamethasone and the pro-proliferation effect of vitamin C.In vitro experiments show that ROUMN has a higher efficiency in suppressing lipopolysaccharide(LPS)-induced interleukin-6(IL-6)expression than dexamethasone alone.Cell proliferation and migrationwere also significantly promoted byROUMNcompared to vitamin C alone.The healing-promoting effect of ROUMN was also verified in vivo using an acetic acid-cauterized oral ulcer model in rats.ROUMN as a treatment accelerated the healing process of oral ulcers,shortening the total healing time to 5 days compared with the 7 days required by treatment using watermelon frost,a commonly used over-the-counter(OTC)drug for oral ulcers.The rapid dissolution of the hyaluronic acid-based microneedles and the superior healing-promoting effect of the drug combination could lead to a broad application prospect of the ROUMN patch in the treatment of recurrent oral ulcers.

Near-infrared responsive 5-fluorouracil and indocyanine green loaded MPEG-PCL nanoparticle integrated with dissolvable microneedle for skin cancer therapy

The prevalence of skin cancer is rising along with the rapid population aging in recent years.Traditional therapies,such as surgical treatment,radiotherapy,chemotherapy,photodynamic therapy,and immunotherapy,may accompany serious side effects,limiting their clinical benefits.According to the biological characteristics of skin cancer,we have already established two kinds of synergetic systems of photothermal therapy(microneedle)and chemotherapy,containing gold nanorods(GNR).Although the microneedle system exhibited great potential for skin cancer treatment,the system could be still improved further.So,we designed a near-infrared lightresponsive 5-fluorouracil(5-Fu)and indocyanine green(ICG)loaded monomethoxy-poly(ethylene glycol)-polycaprolactone(MPEG-PCL)nanoparticle(5-Fu-ICG-MPEG-PCL),and then 5-Fu-ICG-MPEG-PCL was integrated with a hyaluronic acid dissolvable microneedle system(HA MN)to get 5-Fu-ICG-MPEG-PCL loaded HA MN for treating skin cancers,including human epidermoid cancer and melanoma.In this system,hyaluronic acid,the microneedle carrier,possesses good skin penetration ability and is approved by FDA as a pharmaceutical adjuvant;5-Fu is recommended by FDA for skin cancer treatment;ICG,a photothermal agent,possesses a strong photothermal ability and is approved by FDA for its use in the human body.We hypothesized that 5-Fu-ICG-MPEG-PCL could be delivered by the dissolvable microneedle through the skin,and the release behavior of the drug in the nanoparticle could be controlled by near-infrared light for achieving a single-dose cure of skin cancer,improving the cure rate of skin cancer and providing a new idea and possibility for the clinical treatment of skin cancer.

Self-assembly nanomicelle-microneedle patches with enhanced tumor penetration for superior chemo-photothermal therapy

Nanomedicine with high specificity has been a promising tool for cancer diagnosis and therapy.However,the successful application of nanoparticle-based superficial cancer therapy is severely hindered by restricted deep tumor tissue accumulation and penetration.Herein,a self-assembly nanomicelle dissolving microneedle(DMN)patch according to the“nano in micro”strategy was conducted to co-deliver a first-line chemotherapeutic agent paclitaxel(PTX),and a photosensitizer IR780(PTX/IR780-NMs@DMNs)for chemo-photothermal synergetic melanoma therapy.Upon direct insertion into the tumor site,DMNs created a regular and multipoint three-dimensional drug depot to maximize the tumor accumulation.Accompanied by the DMN dissolution,the composition of the needle matrixes self-assembled into nanomicelles,which could efficiently penetrate deep tumor tissue.Upon laser irradiation,the nanomicelles could not only ablate tumor cells directly by photothermal conversion but also trigger PTX release to induce tumor cell apoptosis.In vivo results showed that compared with intravenous injection,IR780 delivered by PTX/IR780-NMs@DMNs was almost completely accumulated at the tumor site.The antitumor results revealed that the PTX/IR780-NMs@DMNs could effectively eliminate tumors with an 88%curable rate without any damage to normal tissues.This work provides a versatile and generalizable framework for designing self-assembly DMN-mediated combination therapy to fight against superficial cancer.