In vitro and in vivo testing of a novel local nicardipine delivery system to the brain: a preclinical study

Restricted access

OBJECTIVE

The management of patients with aneurysmal subarachnoid hemorrhage (aSAH) remains a highly demanding challenge in critical care medicine. Despite all efforts, the calcium channel antagonist nimodipine remains the only drug approved for improving outcomes after aSAH. However, in its current form of application, it provides less than optimal efficacy and causes dose-limiting hypotension in a substantial number of patients. Here, the authors tested in vitro the release dynamics of a novel formulation of the calcium channel blocker nicardipine and in vivo local tolerance and tissue reaction using a chronic cranial window model in mice.

METHODS

To characterize the release kinetics in vitro, dissolution experiments were performed using artificial cerebrospinal fluid over a time period of 21 days. The excipients used in this formulation (NicaPlant) for sustained nicardipine release are a mixture of two completely degradable polymers. A chronic cranial window in C57BL/6 mice was prepared, and NicaPlant slices were placed in proximity to the exposed cerebral vasculature. Epifluorescence video microscopy was performed right after implantation and on days 3 and 7 after surgery. Vessel diameter of the arteries and veins, vessel permeability, vessel configuration, and leukocyte–endothelial cell interaction were quantified by computer-assisted analysis. Immunofluorescence staining was performed to analyze inflammatory reactions and neuronal alterations.

RESULTS

In vitro the nicardipine release profile showed an almost linear curve with about 80% release at day 15 and full release at day 21. In vivo epifluorescence video microscopy showed a significantly higher arterial vessel diameter in the NicaPlant group due to vessel dilatation (21.6 ± 2.6 µm vs 17.8 ± 1.5 µm in controls, p < 0.01) confirming vasoactivity of the implant, whereas the venous diameter was not affected. Vessel dilatation did not have any influence on the vessel permeability measured by contrast extravasation of the fluorescent dye in epifluorescence microscopy. Further, an increased leukocyte–endothelial cell interaction due to the implant could not be detected. Histological analysis did not show any microglial activation or accumulation. No structural neuronal changes were observed.

CONCLUSIONS

NicaPlant provides continuous in vitro release of nicardipine over a 3-week observation period. In vivo testing confirmed vasoactivity and lack of toxicity. The local application of this novel nicardipine delivery system to the subarachnoid space is a promising tool to improve patient outcomes while avoiding systemic side effects.

ABBREVIATIONS aCSF = artificial cerebrospinal fluid; aSAH = aneurysmal subarachnoid hemorrhage; cGMP = current good manufacturing practice; EVD = external ventricular drain; IEFVM = intravital epi-illumination fluorescence video microscopy; FITC = fluorescein isothiocyanate; NPRI = nicardipine prolonged-release implant; PBS = phosphate-buffered saline; PLGA = poly(d,l-lactide-co-glycolide) 50:50.
Article Information

Contributor Notes

Correspondence Peter Vajkoczy: Charité–Universitätsmedizin Berlin, Germany. peter.vajkoczy@charite.de.INCLUDE WHEN CITING Published online January 25, 2019; DOI: 10.3171/2018.9.JNS173085.Disclosures Dr. Breitenbach is co-founder and chief executive officer of BIT Pharma. Dr. Vajkoczy is co-founder of and clinical consultant for BIT Pharma. Dr. Adage is an employee of BIT Pharma. All other authors have no conflicts of interest to declare.
Headings
References
  • 1

    Atangana ESchneider UCBlecharz KMagrini SWagner JNieminen-Kelhä M: Intravascular inflammation triggers intracerebral activated microglia and contributes to secondary brain injury after experimental subarachnoid hemorrhage (eSAH). Transl Stroke Res 8:1441562017

    • Search Google Scholar
    • Export Citation
  • 2

    Barth MCapelle HHWeidauer SWeiss CMünch EThomé C: Effect of nicardipine prolonged-release implants on cerebral vasospasm and clinical outcome after severe aneurysmal subarachnoid hemorrhage: a prospective, randomized, double-blind phase IIa study. Stroke 38:3303362007

    • Search Google Scholar
    • Export Citation
  • 3

    Bayerl SHNieminen-Kelhä MBroggini TVajkoczy PPrinz V: Lateral chronic cranial window preparation enables in vivo observation following distal middle cerebral artery occlusion in mice. J Vis Exp (118):e547012016

    • Search Google Scholar
    • Export Citation
  • 4

    Bayerl SHNiesner RCseresnyes ZRadbruch HPohlan JBrandenburg S: Time lapse in vivo microscopy reveals distinct dynamics of microglia-tumor environment interactions—a new role for the tumor perivascular space as highway for trafficking microglia. Glia 64:121012262016

    • Search Google Scholar
    • Export Citation
  • 5

    Dreier JPWoitzik JFabricius MBhatia RMajor SDrenckhahn C: Delayed ischaemic neurological deficits after subarachnoid haemorrhage are associated with clusters of spreading depolarizations. Brain 129:322432372006

    • Search Google Scholar
    • Export Citation
  • 6

    Hänggi DEtminan NAldrich FSteiger HJMayer SADiringer MN: Randomized, open-label, phase 1/2a study to determine the maximum tolerated dose of intraventricular sustained release nimodipine for subarachnoid hemorrhage (NEWTON [Nimodipine Microparticles to Enhance Recovery While Reducing Toxicity After Subarachnoid Hemorrhage]). Stroke 48:1451512017

    • Search Google Scholar
    • Export Citation
  • 7

    Huang BRChang PCYeh WLLee CHTsai CFLin C: Anti-neuroinflammatory effects of the calcium channel blocker nicardipine on microglial cells: implications for neuroprotection. PLoS One 9:e911672014

    • Search Google Scholar
    • Export Citation
  • 8

    Kasuya HOnda HSasahara ATakeshita MHori T: Application of nicardipine prolonged-release implants: analysis of 97 consecutive patients with acute subarachnoid hemorrhage. Neurosurgery 56:8959022005

    • Search Google Scholar
    • Export Citation
  • 9

    Kasuya HOnda HTakeshita MOkada YHori T: Efficacy and safety of nicardipine prolonged-release implants for preventing vasospasm in humans. Stroke 33:101110152002

    • Search Google Scholar
    • Export Citation
  • 10

    Lovelock CERinkel GJERothwell PM: Time trends in outcome of subarachnoid hemorrhage: Population-based study and systematic review. Neurology 74:149415012010

    • Search Google Scholar
    • Export Citation
  • 11

    Sandow NDiesing DSarrafzadeh AVajkoczy PWolf S: Nimodipine dose reductions in the treatment of patients with aneurysmal subarachnoid hemorrhage. Neurocrit Care 25:29392016

    • Search Google Scholar
    • Export Citation
  • 12

    Schneider UCDavids AMBrandenburg SMüller AElke AMagrini S: Microglia inflict delayed brain injury after subarachnoid hemorrhage. Acta Neuropathol 130:2152312015

    • Search Google Scholar
    • Export Citation
  • 13

    Schneider UCDreher SHoffmann KTSchmiedek PKasuya HVajkoczy P: The use of nicardipine prolonged release implants (NPRI) in microsurgical clipping after aneurysmal subarachnoid haemorrhage: comparison with endovascular treatment. Acta Neurochir (Wien) 153:211921252011

    • Search Google Scholar
    • Export Citation
  • 14

    Suarez JITarr RWSelman WR: Aneurysmal subarachnoid hemorrhage. N Engl J Med 354:3873962006

  • 15

    Thomé CSeiz MSchubert GABarth MVajkoczy PKasuya H: Nicardipine pellets for the prevention of cerebral vasospasm. Acta Neurochir Suppl 110:2092112011

    • Search Google Scholar
    • Export Citation
  • 16

    Vajkoczy PSchilling LUllrich ASchmiedek PMenger MD: Characterization of angiogenesis and microcirculation of high-grade glioma: an intravital multifluorescence microscopic approach in the athymic nude mouse. J Cereb Blood Flow Metab 18:5105201998

    • Search Google Scholar
    • Export Citation
  • 17

    Woitzik JDreier JPHecht NFiss ISandow NMajor S: Delayed cerebral ischemia and spreading depolarization in absence of angiographic vasospasm after subarachnoid hemorrhage. J Cereb Blood Flow Metab 32:2032122012

    • Search Google Scholar
    • Export Citation
TrendMD
Metrics

Metrics

All Time Past Year Past 30 Days
Abstract Views 61 61 61
Full Text Views 26 26 26
PDF Downloads 25 25 25
EPUB Downloads 0 0 0
PubMed
Google Scholar