John Bianco

Nanoparticle transport across in vitro olfactory cell monolayers.

Drug access to the CNS is hindered by the presence of the blood-brain barrier (BBB), and the intranasal route has risen as a non-invasive route to transport drugs directly from nose-to-brain avoiding the BBB. In addition, nanoparticles (NPs) have been described as efficient shuttles for direct nose-to-brain delivery of drugs. Nevertheless, there are few studies describing NP nose-to-brain transport. Thus, the aim of this work was (i) to develop, characterize and validate in vitro olfactory cell monolayers and (ii) to study the transport of polymeric- and lipid-based NPs across these monolayers in order to estimate NP access into the brain using cell penetrating peptide (CPPs) moieties: Tat and Penetratin (Pen). All tested poly(d,l-lactide-co-glycolide) (PLGA) and nanostructured lipid carrier (NLC) formulations were stable in transport buffer and biocompatible with the olfactory mucosa cells. Nevertheless, 0.7% of PLGA NPs was able to cross the olfactory cell monolayers, whereas 8% and 22% of NLC and chitosan-coated NLC (CS-NLC) were transported across them, respectively. Moreover, the incorporation of CPPs to NLC surface significantly increased their transport, reaching 46% of transported NPs. We conclude that CPP-CS-NLC represent a promising brain shuttle via nose-to-brain for drug delivery.

Injectable nanomedicine hydrogel for local chemotherapy of glioblastoma after surgical resection

&NA; Glioblastoma (GBM) treatment includes, when possible, surgical resection of the tumor followed by radiotherapy and oral chemotherapy with temozolomide, however recurrences quickly develop around the resection cavity borders leading to patient death. We hypothesize that the local delivery of Lauroyl‐gemcitabine lipid nanocapsule based hydrogel (GemC12‐LNC) in the tumor resection cavity of GBM is a promising strategy as it would allow to bypass the blood brain barrier, thus reaching high local concentrations of the drug. The cytotoxicity and internalization pathways of GemC12‐LNC were studied on different GBM cell lines (U251, T98‐G, 9L‐LacZ, U‐87 MG). The GemC12‐LNC hydrogel was well tolerated when injected in mouse brain. In an orthotopic xenograft model, after intratumoral administration, GemC12‐LNC significantly increased mice survival compared to the controls. Moreover, its ability to delay tumor recurrences was demonstrated after perisurgical administration in the GBM resection cavity. In conclusion, we demonstrate that GemC12‐LNC hydrogel could be considered as a promising tool for the post‐resection management of GBM, prior to the standard of care chemo‐radiation. Graphical abstract Figure. No caption available.

Taking a bite out of spinal cord injury: do dental stem cells have the teeth for it?

Dental stem cells are an emerging star on a stage that is already quite populated. Recently, there has been a lot of hype concerning these cells in dental therapies, especially in regenerative endodontics. It is fitting that most research is concentrated on dental regeneration, although other uses for these cells need to be explored in more detail. Being a true mesenchymal stem cell, their capacities could also prove beneficial in areas outside their natural environment. One such field is the central nervous system, and in particular, repairing the injured spinal cord. One of the most formidable challenges in regenerative medicine is to restore function to the injured spinal cord, and as yet, a cure for paralysis remains to be discovered. A variety of approaches have already been tested, with graft-based strategies utilising cells harbouring appropriate properties for neural regeneration showing encouraging results. Here we present a review focusing on properties of dental stem cells that endorse their use in regenerative medicine, with particular emphasis on repairing the damaged spinal cord.

Novel model of orthotopic U-87 MG glioblastoma resection in athymic nude mice.

In vitro and in vivo models of experimental glioma are useful tools to gain a better understanding of glioblastoma (GBM) and to investigate novel treatment strategies. However, the majority of preclinical models focus on treating solid intracranial tumours, despite surgical resection being the mainstay in the standard care of patients with GBM today. The lack of resection and recurrence models therefore has undermined efforts in finding a treatment for this disease. Here we present a novel orthotopic tumour resection and recurrence model that has potential for the investigation of local delivery strategies in the treatment of GBM. The model presented is simple to achieve through the use of a biopsy punch, is reproducible, does not require specific or expensive equipment, and results in a resection cavity suitable for local drug delivery systems, such as the implantation or injection of hydrogels. We show that tumour resection is well tolerated, does not induce deleterious neurological deficits, and significantly prolongs survival of mice bearing U-87 MG GBM tumours. In addition, the resulting cavity could accommodate adequate amounts of hydrogels for local delivery of chemotherapeutic agents to eliminate residual tumour cells that can induce tumour recurrence.

Rapid Serum-Free Isolation of Oligodendrocyte Progenitor Cells from Adult Rat Spinal Cord.

Oligodendrocyte progenitor cells (OPCs) play a pivotal role in both health and disease within the central nervous system, with oligodendrocytes, arising from resident OPCs, being the main myelinating cell type. Disruption in OPC numbers can lead to various deleterious health defects. Numerous studies have described techniques for isolating OPCs to obtain a better understanding of this cell type and to open doors for potential treatments of injury and disease. However, the techniques used in the majority of these studies involve several steps and are time consuming, with current culture protocols using serum and embryonic or postnatal cortical tissue as a source of isolation. We present a primary culture method for the direct isolation of functional adult rat OPCs, identified by neuron-glial antigen 2 (NG2) and platelet derived growth factor receptor alpha (PDGFrα) expression, which can be obtained from the adult spinal cord. Our method uses a simple serum-free cocktail of 3 growth factors – FGF2, PDGFAA, and IGF-I, to expand adult rat OPCs in vitro to 96% purity. Cultured cells can be expanded for at least 10 passages with very little manipulation and without losing their phenotypic progenitor cell properties, as shown by immunocytochemistry and RT-PCR. Cultured adult rat OPCs also maintain their ability to differentiate into GalC positive cells when incubated with factors known to stimulate their differentiation. This new isolation method provides a new source of easily accessible adult stem cells and a powerful tool for their expansion in vitro for studies aimed at central nervous system repair.

Evaluation of lauroyl-gemcitabine-loaded hydrogel efficacy in glioblastoma rat models

AIM Anticancer drug-loaded hydrogels are a promising strategy for the local treatment of incurable brain tumors such as glioblastoma (GBM). Recently, we demonstrated the efficacy of lauroyl-gemcitabine lipid nanocapsule hydrogel (GemC12-LNC) in a U-87 MG xenograft orthotopic mouse model. In this study, we developed a reliable and reproducible surgical procedure to resect orthotopic GBM tumors in rats. GemC12-LNC hydrogel integrity was tested after brain administration in rats and its anti-tumor efficacy was tested on a 9L syngeneic orthotopic model. RESULTS We demonstrated that LNC integrity is maintained at least for one week after local administration of GemC12-LNC. GemC12-LNC was able to delay the formation of recurrences in 9L tumor-bearing resected rats, demonstrating the efficacy of this nanomedicine hydrogel in this preclinical model. CONCLUSION Our results confirm that GemC12-LNC, a hydrogel uniquely formed by a nanocarrier and a cytotoxic drug, could be a promising and safe delivery tool for the local treatment of operable GBM tumors.

Post-resection treatment of glioblastoma with an injectable nanomedicine-loaded photopolymerizable hydrogel induces long-term survival

ABSTRACT Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor. Despite available therapeutic options, the prognosis for patients with GBM remains very poor. We hypothesized that the intra‐operative injection of a photopolymerizable hydrogel into the tumor resection cavity could sustain the release of the anti‐cancer drug paclitaxel (PTX) encapsulated in poly (lactic‐co‐glycolic acid) (PLGA) nanoparticles and prevent GBM recurrence. The tumor was resected 13days after implantation and a pre‐gel solution composed of polyethylene glycol dimethacrylate (PEG‐DMA) polymer, a photoinitiator and PTX‐loaded PLGA nanoparticles (PTX PLGA‐NPs) was injected into the tumor resection cavity. A solid gel filling the whole cavity was formed immediately by photopolymerization using a 400nm light. PTX in vitro release study showed a burst release (11%) in the first 8h and a sustained release of 29% over a week. In vitro, U87 MG cells were sensitive to PTX PLGA‐NPs with IC50 level of approximately 0.010&mgr;g/mL. The hydrogel was well‐tolerated when implanted in the brain of healthy mice for 2 and 4months. Administration of PTX PLGA‐NPs‐loaded hydrogel into the resection cavity of GBM orthotopic model lead to more than 50% long‐term survival mice (150days) compared to the control groups (mean survival time 52days). This significant delay of recurrence is very promising for the post‐resection treatment of GBM.

Magnetic targeting of paclitaxel-loaded poly(lactic- co -glycolic acid)-based nanoparticles for the treatment of glioblastoma

Introduction Glioblastoma (GBM) therapy is highly challenging, as the tumors are very aggressive due to infiltration into the surrounding normal brain tissue. Even a combination of the available therapeutic regimens may not debulk the tumor completely. GBM tumors are also known for recurrence, resulting in survival rates averaging <18 months. In addition, systemic chemotherapy for GBM has been challenged for its minimal desired therapeutic effects and unwanted side effects. Purpose We hypothesized that paclitaxel (PTX) and superparamagnetic iron oxide (SPIO)-loaded PEGylated poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles (NPs; PTX/SPIO-NPs) can serve as an effective nanocarrier system for magnetic targeting purposes, and we aimed to demonstrate the therapeutic efficacy of this system in an orthotopic murine GBM model. Materials and methods PTX/SPIO-NPs were prepared by emulsion–diffusion–evaporation method and characterized for physicochemical properties. In vitro cellular uptake of PTX/SPIO-NPs was evaluated by fluorescence microscopy and Prussian blue staining. Orthotopic U87MG tumor model was used to evaluate blood–brain barrier disruption using T1 contrast agent, ex vivo biodistribution, in vivo toxicity and in vivo antitumor efficacy of PTX/SPIO-NPs. Results PTX/SPIO-NPs were in the size of 250 nm with negative zeta potential. Qualitative cellular uptake studies showed that the internalization of NPs was concentration dependent. Through magnetic resonance imaging, we observed that the blood–brain barrier was disrupted in the GBM area. An ex vivo biodistribution study showed enhanced accumulation of NPs in the brain of GBM-bearing mice with magnetic targeting. Short-term in vivo safety evaluation showed that the NPs did not induce any systemic toxicity compared with Taxol® (PTX). When tested for in vivo efficacy, the magnetic targeting treatment significantly prolonged the median survival time compared with the passive targeting and control treatments. Conclusion Overall, PTX/SPIO-NPs with magnetic targeting could be considered as an effective anticancer targeting strategy for GBM chemotherapy.

Author Correction: Stem cells from human apical papilla decrease neuro‑inflammation and stimulate oligodendrocyte progenitor differentiation via activin‑A secretion

In the original publication, sixth author’s surname was incorrectly published as “Llyod” instead of “Lloyd”. The correct name should read as “Amy Lloyd”.