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Gao G, Zhang L, Li Z, Ma S, Ma F. Porous Microneedles for Therapy and Diagnosis: Fabrication and Challenges. ACS Biomater Sci Eng 2023; 9:85-105. [PMID: 36475572 DOI: 10.1021/acsbiomaterials.2c01123] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The use of microneedles (MNs), an innovative transdermal technology, enables efficient, convenient, painless, and controlled-release drug delivery. Porous microneedles (pMNs), special MNs with abundant interconnected pores that can produce capillary action, are gaining increasing attention as a novel MNs technology. pMNs can actively adsorb bioactive ingredients from solutions of drugs or vaccines for in vivo delivery or from interstitial skin fluids (ISFs) for wearable and point-of-care testing (POCT) products. Different pore sizes and porosities of pMNs can be achieved with different materials and preparation processes, which makes the application of pMNs adaptable to multiple scenarios. In addition, easier and faster detection will be accomplished by the smart combination of pMNs with other detection technologies. This paper aims to summarize the recent research progress of pMNs, focusing on the influence of various materials and their corresponding preparation methods on its structure and function display, discussing the key issues and looking forward to the future development.
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Affiliation(s)
- Guangzhi Gao
- Laboratory of Biologics and Biomaterials, College of Pharmacy, Zhejiang University of Technology, Deqing 313216, China
| | - Li Zhang
- Laboratory of Biologics and Biomaterials, College of Pharmacy, Zhejiang University of Technology, Deqing 313216, China
| | - Zhipeng Li
- Laboratory of Biologics and Biomaterials, College of Pharmacy, Zhejiang University of Technology, Deqing 313216, China
| | - Shichao Ma
- Laboratory of Biologics and Biomaterials, College of Pharmacy, Zhejiang University of Technology, Deqing 313216, China
| | - Fengsen Ma
- Laboratory of Biologics and Biomaterials, College of Pharmacy, Zhejiang University of Technology, Deqing 313216, China.,The Institute for Frontiers and Interdisciplinary Sciences, Zhejiang University of Technology, No. 18, Chaowang Road, Hangzhou 310014, China
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He YT, Liang L, Zhao ZQ, Hu LF, Fei WM, Chen BZ, Cui Y, Guo XD. Advances in porous microneedle systems for drug delivery and biomarker detection: A mini review. J Drug Deliv Sci Technol 2022. [DOI: 10.1016/j.jddst.2022.103518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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3
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Sadeqi A, Kiaee G, Zeng W, Rezaei Nejad H, Sonkusale S. Hard polymeric porous microneedles on stretchable substrate for transdermal drug delivery. Sci Rep 2022; 12:1853. [PMID: 35115643 PMCID: PMC8813900 DOI: 10.1038/s41598-022-05912-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 01/13/2022] [Indexed: 12/18/2022] Open
Abstract
Microneedles offer a convenient transdermal delivery route with potential for long term sustained release of drugs. However current microneedle technologies may not have the mechanical properties for reliable and stable penetration (e.g. hydrogel microneedles). Moreover, it is also challenging to realize microneedle arrays with large size and high flexibility. There is also an inherent upper limit to the amount and kind of drugs that can be loaded in the microneedles. In this paper, we present a new class of polymeric porous microneedles made from biocompatible and photo-curable resin that address these challenges. The microneedles are unique in their ability to load solid drug formulation in concentrated form. We demonstrate the loading and release of solid formulation of anesthetic and non-steroidal anti-inflammatory drugs, namely Lidocaine and Ibuprofen. Paper also demonstrates realization of large area (6 × 20 cm2) flexible and stretchable microneedle patches capable of drug delivery on any body part. Penetration studies were performed in an ex vivo porcine model supplemented through rigorous compression tests to ensure the robustness and rigidity of the microneedles. Detailed release profiles of the microneedle patches were shown in an in vitro skin model. Results show promise for large area transdermal delivery of solid drug formulations using these porous microneedles.
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Affiliation(s)
- Aydin Sadeqi
- Nano Lab, Advanced Technology Laboratory, Tufts University, 200 Boston Avenue, Medford, MA, 02155, USA.,Department of Electrical and Computer Engineering, Tufts University, 161 College Ave, Medford, MA, 02155, USA
| | - Gita Kiaee
- Nano Lab, Advanced Technology Laboratory, Tufts University, 200 Boston Avenue, Medford, MA, 02155, USA
| | - Wenxin Zeng
- Nano Lab, Advanced Technology Laboratory, Tufts University, 200 Boston Avenue, Medford, MA, 02155, USA.,Department of Electrical and Computer Engineering, Tufts University, 161 College Ave, Medford, MA, 02155, USA
| | - Hojatollah Rezaei Nejad
- Nano Lab, Advanced Technology Laboratory, Tufts University, 200 Boston Avenue, Medford, MA, 02155, USA. .,Anodyne Nanotech Inc, 38 Wareham St, Boston, MA, 02118, USA.
| | - Sameer Sonkusale
- Nano Lab, Advanced Technology Laboratory, Tufts University, 200 Boston Avenue, Medford, MA, 02155, USA. .,Department of Electrical and Computer Engineering, Tufts University, 161 College Ave, Medford, MA, 02155, USA.
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Bao L, Park J, Bonfante G, Kim B. Recent advances in porous microneedles: materials, fabrication, and transdermal applications. Drug Deliv Transl Res 2022; 12:395-414. [PMID: 34415566 PMCID: PMC8724174 DOI: 10.1007/s13346-021-01045-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2021] [Indexed: 12/20/2022]
Abstract
In the past two decades, microneedles (MNs), as a painless and simple drug delivery system, have received increasing attention for various biomedical applications such as transdermal drug delivery, interstitial fluid (ISF) extraction, and biosensing. Among the various types of MNs, porous MNs have been recently researched owing to their distinctive and unique characteristics, where porous structures inside MNs with continuous nano- or micro-sized pores can transport drugs or biofluids by capillary action. In addition, a wide range of materials, including non-polymers and polymers, were researched and used to form the porous structures of porous MNs. Adjustable porosity by different fabrication methods enables the achievement of sufficient mechanical strength by optimising fluid flows inside MNs. Moreover, biocompatible porous MNs integrated with biosensors can offer portable detection and rapid measurement of biomarkers in a minimally invasive manner. This review focuses on several aspects of current porous MN technology, including material selection, fabrication processes, biomedical applications, primarily covering transdermal drug delivery, ISF extraction, and biosensing, along with future prospects as well as challenges.
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Affiliation(s)
- Leilei Bao
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan
| | - Jongho Park
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan
| | | | - Beomjoon Kim
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan.
- LIMMS/CNRS-IIS UMI 2820, The University of Tokyo, Tokyo, Japan.
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5
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Microfluidic chip connected to porous microneedle array for continuous ISF sampling. Drug Deliv Transl Res 2021; 12:435-443. [PMID: 34739717 DOI: 10.1007/s13346-021-01050-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2021] [Indexed: 10/19/2022]
Abstract
Minimally invasive biosensing using microneedles (MNs) is a desirable technology for continuous healthcare monitoring. Among a wide range of MNs, porous MNs are expected to be applied for sampling of interstitial fluids (ISF) by connecting the internal tissue to external measurement devices. In order to realize a continuous measurement of biomarkers in ISF through porous MNs, their integration with a microfluidic chip is a promising approach due to its applicability to micro-total analysis system (μTAS) technology. In this study, we developed a fluidic system to directly interface porous MNs to a microfluidic chip consisting of a capillary pump for the continuous sampling of ISF. The porous and flexible MNs made of PDMS are connected to the microfluidic chip fabricated by standard microelectro-mechanical system (MEMS) processes, showing a continuous flow of phosphate buffered saline (PBS). The developed device will lead to the minimally invasive and continuous biosampling for long-term healthcare monitoring.
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Sabri AHB, Anjani QK, Donnelly RF. Synthesis and characterization of sorbitol laced hydrogel-forming microneedles for therapeutic drug monitoring. Int J Pharm 2021; 607:121049. [PMID: 34454026 DOI: 10.1016/j.ijpharm.2021.121049] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/20/2021] [Accepted: 08/23/2021] [Indexed: 11/24/2022]
Abstract
The dermal interstitial fluid (ISF) is rich in biomarkers that are of great heuristic value for disease diagnosis and therapeutic drug monitoring. Nevertheless, the current strategies for sampling dermal ISF are both technical and invasive, limiting the potential utility of ISF for clinical medicine and research purposes. In the current work, we present, for the first time, the development, characterization, and evaluation of a novel sorbitol-laced hydrogel-forming microneedles (Sor-Hyd-MN) for sampling dermal ISF. The hydrogel system is fabricated from sorbitol and PEG 10,000 crosslinked with Gantrez® S-97 via esterification in a solvent-free manner. The sorbitol-laced hydrogel rapidly absorbs fluid when placed in aqueous media, reaching a total rise in the mass of 685% relative to the control hydrogel that only reached 436% within 15 mins. When formulated into MNs, the Sor-Hyd-MN exhibited significantly superior (p < 0.001) mechanical properties as evidenced by the minimal MN height reduction (0.9%) relative to the control-MN (3.9%) and Man-Hyd-MN (28.5%) when subjected to a compressive force of 32 N, an analog of patients' thumb pressure. The skin insertion capability of the Sor-Hyd-MN and the control-MN formulation was demonstrated using the in vitro skin simulant, Parafilm® M, and ex vivo neonatal porcine skin. When inserted into ex vivo neonatal porcine skin, the Sor-Hyd-MN showed rapid imbibement of dermal ISF within 15 mins, evidenced via the formation of swollen microchannels, which was 1.2-folds wider than the control formulation. In addition, we also demonstrated for the first time that incorporating sorbitol into Gantrez® S-97 hydrogel-forming MN improved the utility of this formulation in sampling dermal ISF. This was shown from the capability of the Sor-Hyd-MN in extracting the model compounds, isoniazid and theophylline, present within the ISF of ex vivo porcine skin. The Sor-Hyd-MN exhibited an extraction efficiency of 52.4% for isoniazid and 54.4% for theophylline which was significantly higher (p < 0.05) relative to the control formulation in a simple and straightforward manner. This work illustrates that incorporating a hyperosmolyte, such as sorbitol, can further enhance the potential utility of hydrogel-forming MN as a minimally-invasive tool for ISF sampling while providing a potential strategy to extract analytes with ease for subsequent sample analysis.
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Affiliation(s)
- Akmal Hidayat Bin Sabri
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Qonita Kurnia Anjani
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK; Department of Pharmaceutics, Faculty of Pharmacy, Hasanuddin University, Makassar, Indonesia
| | - Ryan F Donnelly
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK.
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Liu P, Du H, Chen Y, Wang H, Mao J, Zhang L, Tao J, Zhu J. Polymer microneedles with interconnected porous structures via a phase inversion route for transdermal medical applications. J Mater Chem B 2021; 8:2032-2039. [PMID: 32049084 DOI: 10.1039/c9tb02837d] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Porous polymer microneedles (MNs) have great potential in transdermal medical applications due to their three-dimensional (3D) porous structures and high porosity. However, existing approaches for the fabrication of such porous polymer MNs are complicated and only applicable to limited types of polymers. Here, we describe a facile yet effective phase inversion route to prepare polymer MNs with highly porous and interconnected pore structures. The fabrication process is simple and mild without involving high temperatures or irradiation, and can be applied to a broad spectrum of commonly used polymers (e.g., cellulose acetate (CA), polysulfone (PSF), polyethersulfone (PES), polylactic acid (PLA), etc.). Thanks to the capillary effect and large cavity given by highly porous and interconnected structures, the resulting porous polymer MNs show the capability of rapidly extracting dermal interstitial fluid (ISF) and efficiently loading/releasing drug compounds. As a proof of concept, we demonstrate the use of these porous CA MNs in the highly efficient extraction of ISF for glucose level detection and administration of insulin for hyperglycemia. Given the recent trend of painless techniques in diagnosis and treatment, the current study provides a new opportunity for the fabrication of MN-based devices for transdermal ISF extraction and drug delivery.
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Affiliation(s)
- Pei Liu
- Key Laboratory of Material Chemistry for Energy Conversion and Storage of Ministry of Education (HUST), and State Key Laboratory of Materials Processing and Mold Technology, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China.
| | - Hongyao Du
- Department of Dermatology, Union Hospital, Tongji Medical College, HUST, Wuhan 430022, China
| | - Yu Chen
- Key Laboratory of Material Chemistry for Energy Conversion and Storage of Ministry of Education (HUST), and State Key Laboratory of Materials Processing and Mold Technology, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China.
| | - Hua Wang
- Key Laboratory of Material Chemistry for Energy Conversion and Storage of Ministry of Education (HUST), and State Key Laboratory of Materials Processing and Mold Technology, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China.
| | - Jinzhu Mao
- Department of Dermatology, Union Hospital, Tongji Medical College, HUST, Wuhan 430022, China
| | - Lianbin Zhang
- Key Laboratory of Material Chemistry for Energy Conversion and Storage of Ministry of Education (HUST), and State Key Laboratory of Materials Processing and Mold Technology, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China.
| | - Juan Tao
- Department of Dermatology, Union Hospital, Tongji Medical College, HUST, Wuhan 430022, China
| | - Jintao Zhu
- Key Laboratory of Material Chemistry for Energy Conversion and Storage of Ministry of Education (HUST), and State Key Laboratory of Materials Processing and Mold Technology, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China.
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8
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Flexible and porous microneedles of PDMS for continuous glucose monitoring. Biomed Microdevices 2020; 22:79. [PMID: 33141313 DOI: 10.1007/s10544-020-00532-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/2020] [Indexed: 02/08/2023]
Abstract
Microneedle (MN) is a key technology of the biomedical engineering field due to its capability of accessing the biological information in a minimally invasive manner. One of the huge demands for next-generation healthcare monitoring is continuous monitoring, especially of blood glucose concentration. For this, MN should be kept inserted into the human skin for a certain period of time, enduring stresses induced by daily human motion and at the same time measuring biomarkers in ISF. However, conventional MNs for biosensing are not suitable for a long term insertion due to the rigid structure and biological risks of MN breakage. In this study, a novel MN structure is proposed and investigated by combining flexible "sponge-like" porous PDMS matrix and coating by biodissolving hyaluronic acid (HA). The fabricated porous MNs coated with HA show ideal mechanical characteristics, by which the MNs are rigid enough to penetrate the skin and become flexible after insertion into the skin. It is also shown that the MN array successfully extracts ISF in vitro and in vivo not by capillary action but by repeated compressions. The results show the applicability of the flexible MNs to continuous blood glucose monitoring.
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Liu GS, Kong Y, Wang Y, Luo Y, Fan X, Xie X, Yang BR, Wu MX. Microneedles for transdermal diagnostics: Recent advances and new horizons. Biomaterials 2020; 232:119740. [PMID: 31918227 PMCID: PMC7432994 DOI: 10.1016/j.biomaterials.2019.119740] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 12/21/2019] [Accepted: 12/25/2019] [Indexed: 12/16/2022]
Abstract
Point-of-care testing (POCT), defined as the test performed at or near a patient, has been evolving into a complement to conventional laboratory diagnosis by continually providing portable, cost-effective, and easy-to-use measurement tools. Among them, microneedle-based POCT devices have gained increasing attention from researchers due to the glorious potential for detecting various analytes in a minimally invasive manner. More recently, a novel synergism between microneedle and wearable technologies is expanding their detection capabilities. Herein, we provide an overview on the progress in microneedle-based transdermal biosensors. It covers all the main aspects of the field, including design philosophy, material selection, and working mechanisms as well as the utility of the devices. We also discuss lessons from the past, challenges of the present, and visions for the future on translation of these state-of-the-art technologies from the bench to the bedside.
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Affiliation(s)
- Gui-Shi Liu
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, College of Science & Engineering, Jinan University, Guangzhou, 510632, China
| | - Yifei Kong
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Yensheng Wang
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Yunhan Luo
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, College of Science & Engineering, Jinan University, Guangzhou, 510632, China
| | - Xudong Fan
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Xi Xie
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, China.
| | - Bo-Ru Yang
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, China.
| | - Mei X Wu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA.
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Cheng H, Liu M, Du X, Xu J, Zhai Y, Ji J, He S, Zhai G. Recent progress of micro-needle formulations: Fabrication strategies and delivery applications. J Drug Deliv Sci Technol 2019. [DOI: 10.1016/j.jddst.2019.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Takeuchi K, Kim B. Functionalized microneedles for continuous glucose monitoring. NANO CONVERGENCE 2018; 5:28. [PMID: 30467645 PMCID: PMC6199201 DOI: 10.1186/s40580-018-0161-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 09/26/2018] [Indexed: 05/23/2023]
Abstract
Microneedles (MNs) have been established as promising medical devices as they are minimally invasive, cause less pain, and can be utilized for self-administration of drugs by patients. There has been rapid development in MNs for transdermal monitoring and diagnostic systems, following the active research on fabrication methods and applications for drug delivery. In this paper, recent investigations on bio-sensing using MNs are reviewed in terms of the applicability to continuous glucose monitoring system (CGMS), which is one of the main research focuses of medical engineering technologies. The trend of the functionalized MNs can be categorized as follows: (i) as a sensing probe, and (ii) as a biological fluid collector. MNs as in vivo sensors are mainly integrated or coated with conductive materials to have the function as electrodes. MNs as fluid collectors are given a certain geometrical design, such as a hollow and porous structure aided by a capillary action or negative pressure, to extract the interstitial fluids or blood for ex vivo analysis. For realization of CGMS with MNs, a long-term accurate measurement by the MN-based sensing probe or a fluidic connection between the MN-based fluid collector and the existing microfluidic measurement systems should be investigated.
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Affiliation(s)
- Kai Takeuchi
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505 Japan
| | - Beomjoon Kim
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505 Japan
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Ullah A, Kim CM, Kim GM. Porous polymer coatings on metal microneedles for enhanced drug delivery. ROYAL SOCIETY OPEN SCIENCE 2018; 5:171609. [PMID: 29765638 PMCID: PMC5936903 DOI: 10.1098/rsos.171609] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 03/13/2018] [Indexed: 05/28/2023]
Abstract
We present a simple method to coat microneedles (MNs) uniformly with a porous polymer (PLGA) that can deliver drugs at high rates. Stainless steel (SS) MNs of high mechanical strength were coated with a thin porous polymer layer to enhance their delivery rates. Additionally, to improve the interfacial adhesion between the polymer and MNs, the MN surface was modified by plasma treatment followed by dip coating with polyethyleneimine, a polymer with repeating amine units. The average failure load (the minimum force sufficient for detaching the polymer layer from the surface of SS) recorded for the modified surface coating was 25 N, whereas it was 2.2 N for the non-modified surface. Calcein dye was successfully delivered into porcine skin to a depth of 750 µm by the porous polymer-coated MNs, demonstrating that the developed MNs can pierce skin easily without deformation of MNs; additional skin penetration tests confirmed this finding. For visual comparison, rhodamine B dye was delivered using porous-coated and non-coated MNs in gelatin gel which showed that delivery with porous-coated MNs penetrate deeper when compared with non-coated MNs. Finally, lidocaine and rhodamine B dye were delivered in phosphate-buffered saline (PBS) medium by porous polymer-coated and non-coated MNs. For rhodamine B, drug delivery with the porous-coated MNs was five times higher than that with the non-coated MNs, whereas 25 times more lidocaine was delivered by the porous-coated MNs compared with the non-coated MNs.
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Affiliation(s)
| | | | - Gyu Man Kim
- School of Mechanical Engineering, Kyungpook National University, 80 Deahak-ro, Buk-gu, Daegu 41566, Korea
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Nagamine K, Kubota J, Kai H, Ono Y, Nishizawa M. An array of porous microneedles for transdermal monitoring of intercellular swelling. Biomed Microdevices 2017; 19:68. [PMID: 28776235 DOI: 10.1007/s10544-017-0207-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
An array of porous microneedles was developed for minimally-invasive transdermal electrolytic connection through the human skin barrier, the stratum corneum. The length of microneedle was designed to be 100 μm so that it penetrates into the epidermis layer without pain. Each microneedle was supported by a thicker cylindrical post protruding from a planar substrate to realize its effective penetration even into elastic human skin. Since this support (post and substrate) was equally porous as the needles, the needle chip was entirely permeable for electrolyte. This ion-conductive porous microneedle array was applied to the transdermal conductometry with small direct current for local monitoring of intercellular swelling, edema. The porous needle-based electrode system could be a platform for various transdermal electrical diagnosis and treatments.
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Affiliation(s)
- Kuniaki Nagamine
- Department of Finemechanics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki, Aoba-ku, Sendai, 980-8579, Japan
| | - Jun Kubota
- Department of Finemechanics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki, Aoba-ku, Sendai, 980-8579, Japan
| | - Hiroyuki Kai
- Department of Finemechanics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki, Aoba-ku, Sendai, 980-8579, Japan
| | - Yoshinobu Ono
- Nihon Kohden Co., Ltd., 1-31-4 Nishiochiai, Sinjuku-ku, Tokyo, 161-8560, Japan
| | - Matsuhiko Nishizawa
- Department of Finemechanics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki, Aoba-ku, Sendai, 980-8579, Japan.
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14
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Liu L, Kai H, Nagamine K, Ogawa Y, Nishizawa M. Porous polymer microneedles with interconnecting microchannels for rapid fluid transport. RSC Adv 2016. [DOI: 10.1039/c6ra07882f] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We report a porous polymer microneedle array with continuous micropores that has high mechanical strength and water absorption speed.
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Affiliation(s)
- Liming Liu
- Department of Bioengineering and Robotics
- Graduate School of Engineering
- Tohoku University
- Sendai 980-8579
- Japan
| | - Hiroyuki Kai
- Department of Bioengineering and Robotics
- Graduate School of Engineering
- Tohoku University
- Sendai 980-8579
- Japan
| | - Kuniaki Nagamine
- Department of Bioengineering and Robotics
- Graduate School of Engineering
- Tohoku University
- Sendai 980-8579
- Japan
| | - Yudai Ogawa
- Department of Bioengineering and Robotics
- Graduate School of Engineering
- Tohoku University
- Sendai 980-8579
- Japan
| | - Matsuhiko Nishizawa
- Department of Bioengineering and Robotics
- Graduate School of Engineering
- Tohoku University
- Sendai 980-8579
- Japan
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