Local delivery of minocycline-loaded PLGA nanoparticles from gelatin-coated neural implants attenuates acute brain tissue responses in mice

Abstract Background Neural interfaces often elicit inflammatory responses and neuronal loss in the surrounding tissue which adversely affect the function and longevity of the implanted device. Minocycline, an anti-inflammatory pharmaceutics with neuroprotective properties, may be used for reducing t...

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Main Authors: Alexander Dontsios Holmkvist, Johan Agorelius, Matilde Forni, Ulf J. Nilsson, Cecilia Eriksson Linsmeier, Jens Schouenborg
Format: Article
Language:English
Published: BMC 2020-02-01
Series:Journal of Nanobiotechnology
Subjects:
Online Access:https://doi.org/10.1186/s12951-020-0585-9
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author Alexander Dontsios Holmkvist
Johan Agorelius
Matilde Forni
Ulf J. Nilsson
Cecilia Eriksson Linsmeier
Jens Schouenborg
author_facet Alexander Dontsios Holmkvist
Johan Agorelius
Matilde Forni
Ulf J. Nilsson
Cecilia Eriksson Linsmeier
Jens Schouenborg
author_sort Alexander Dontsios Holmkvist
collection DOAJ
description Abstract Background Neural interfaces often elicit inflammatory responses and neuronal loss in the surrounding tissue which adversely affect the function and longevity of the implanted device. Minocycline, an anti-inflammatory pharmaceutics with neuroprotective properties, may be used for reducing the acute brain tissue responses after implantation. However, conventional administration routes require high doses which can cause adverse systemic side effects. Therefore, the aim of this study was to develop and evaluate a new drug-delivery-system for local and sustained administration of minocycline in the brain. Methods Stainless steel needles insulated with Parylene-C were dip-coated with non-crosslinked gelatin and minocycline-loaded PLGA nanoparticles (MC-NPs) were incorporated into the gelatin-coatings by an absorption method and subsequently trapped by drying the gelatin. Parylene-C insulated needles coated only with gelatin were used as controls. The expression of markers for activated microglia (CD68), all microglia (CX3CR1-GFP), reactive astrocytes (GFAP), neurons (NeuN) and all cell nuclei (DAPI) surrounding the implantation sites were quantified at 3 and 7 days after implantation in mice. Results MC-NPs were successfully incorporated into gelatin-coatings of neural implants by an absorption method suitable for thermosensitive drug-loads. Immunohistochemical analysis of the in vivo brain tissue responses, showed that MC-NPs significantly attenuate the activation of microglial cells without effecting the overall population of microglial cells around the implantation sites. A delayed but significant reduction of the astrocytic response was also found in comparison to control implants. No effect on neurons or total cell count was found which may suggest that the MC-NPs are non-toxic to the central nervous system. Conclusions A novel drug-nanoparticle-delivery-system was developed for neural interfaces and thermosensitive drug-loads. The local delivery of MC-NPs was shown to attenuate the acute brain tissue responses nearby an implant and therefore may be useful for improving biocompatibility of implanted neuro-electronic interfaces. The developed drug-delivery-system may potentially also be used for other pharmaceutics to provide highly localized and therefore more specific effects as compared to systemic administration.
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spelling doaj.art-eb332836fcd74872b36901e684d0631d2022-12-22T02:08:28ZengBMCJournal of Nanobiotechnology1477-31552020-02-0118111210.1186/s12951-020-0585-9Local delivery of minocycline-loaded PLGA nanoparticles from gelatin-coated neural implants attenuates acute brain tissue responses in miceAlexander Dontsios Holmkvist0Johan Agorelius1Matilde Forni2Ulf J. Nilsson3Cecilia Eriksson Linsmeier4Jens Schouenborg5Neuronano Research Center, Department of Experimental Medical Science, Faculty of Medicine, Lund UniversityNeuronano Research Center, Department of Experimental Medical Science, Faculty of Medicine, Lund UniversityNeuronano Research Center, Department of Experimental Medical Science, Faculty of Medicine, Lund UniversityCentre for Analysis and Synthesis, Department of Chemistry, Lund UniversityNeuronano Research Center, Department of Experimental Medical Science, Faculty of Medicine, Lund UniversityNeuronano Research Center, Department of Experimental Medical Science, Faculty of Medicine, Lund UniversityAbstract Background Neural interfaces often elicit inflammatory responses and neuronal loss in the surrounding tissue which adversely affect the function and longevity of the implanted device. Minocycline, an anti-inflammatory pharmaceutics with neuroprotective properties, may be used for reducing the acute brain tissue responses after implantation. However, conventional administration routes require high doses which can cause adverse systemic side effects. Therefore, the aim of this study was to develop and evaluate a new drug-delivery-system for local and sustained administration of minocycline in the brain. Methods Stainless steel needles insulated with Parylene-C were dip-coated with non-crosslinked gelatin and minocycline-loaded PLGA nanoparticles (MC-NPs) were incorporated into the gelatin-coatings by an absorption method and subsequently trapped by drying the gelatin. Parylene-C insulated needles coated only with gelatin were used as controls. The expression of markers for activated microglia (CD68), all microglia (CX3CR1-GFP), reactive astrocytes (GFAP), neurons (NeuN) and all cell nuclei (DAPI) surrounding the implantation sites were quantified at 3 and 7 days after implantation in mice. Results MC-NPs were successfully incorporated into gelatin-coatings of neural implants by an absorption method suitable for thermosensitive drug-loads. Immunohistochemical analysis of the in vivo brain tissue responses, showed that MC-NPs significantly attenuate the activation of microglial cells without effecting the overall population of microglial cells around the implantation sites. A delayed but significant reduction of the astrocytic response was also found in comparison to control implants. No effect on neurons or total cell count was found which may suggest that the MC-NPs are non-toxic to the central nervous system. Conclusions A novel drug-nanoparticle-delivery-system was developed for neural interfaces and thermosensitive drug-loads. The local delivery of MC-NPs was shown to attenuate the acute brain tissue responses nearby an implant and therefore may be useful for improving biocompatibility of implanted neuro-electronic interfaces. The developed drug-delivery-system may potentially also be used for other pharmaceutics to provide highly localized and therefore more specific effects as compared to systemic administration.https://doi.org/10.1186/s12951-020-0585-9Neural interfaceMinocyclineGelatinPLGANanoparticlesDrug-delivery-systems
spellingShingle Alexander Dontsios Holmkvist
Johan Agorelius
Matilde Forni
Ulf J. Nilsson
Cecilia Eriksson Linsmeier
Jens Schouenborg
Local delivery of minocycline-loaded PLGA nanoparticles from gelatin-coated neural implants attenuates acute brain tissue responses in mice
Journal of Nanobiotechnology
Neural interface
Minocycline
Gelatin
PLGA
Nanoparticles
Drug-delivery-systems
title Local delivery of minocycline-loaded PLGA nanoparticles from gelatin-coated neural implants attenuates acute brain tissue responses in mice
title_full Local delivery of minocycline-loaded PLGA nanoparticles from gelatin-coated neural implants attenuates acute brain tissue responses in mice
title_fullStr Local delivery of minocycline-loaded PLGA nanoparticles from gelatin-coated neural implants attenuates acute brain tissue responses in mice
title_full_unstemmed Local delivery of minocycline-loaded PLGA nanoparticles from gelatin-coated neural implants attenuates acute brain tissue responses in mice
title_short Local delivery of minocycline-loaded PLGA nanoparticles from gelatin-coated neural implants attenuates acute brain tissue responses in mice
title_sort local delivery of minocycline loaded plga nanoparticles from gelatin coated neural implants attenuates acute brain tissue responses in mice
topic Neural interface
Minocycline
Gelatin
PLGA
Nanoparticles
Drug-delivery-systems
url https://doi.org/10.1186/s12951-020-0585-9
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