Intraperitoneal Delivery Research Articles

A fully implantable device for intraperitoneal drug delivery refilled by ingestible capsules.

Creating fully implantable robots that replace or restore physiological processes is a great challenge in medical robotics. Restoring blood glucose homeostasis in patients with type 1 diabetes is particularly interesting in this sense. Intraperitoneal insulin delivery could revolutionize type 1 diabetes treatment. At present, the intraperitoneal route is little used because it relies on accessing ports connecting intraperitoneal catheters to external reservoirs. Drug-loaded pills transported across the digestive system to refill an implantable reservoir in a minimally invasive fashion could open new possibilities in intraperitoneal delivery. Here, we describe PILLSID (PILl-refiLled implanted System for Intraperitoneal Delivery), a fully implantable robotic device refillable through ingestible magnetic pills carrying drugs. Once refilled, the device acts as a programmable microinfusion system for precise intraperitoneal delivery. The robotic device is grounded on a combination of magnetic switchable components, miniaturized mechatronic elements, a wireless powering system, and a control unit to implement the refilling and control the infusion processes. In this study, we describe the PILLSID prototyping. The device key blocks are validated as single components and within the integrated device at the preclinical level. We demonstrate that the refilling mechanism works efficiently in vivo and that the blood glucose level can be safely regulated in diabetic swine. The device weights 165 grams and is 78 millimeters by 63 millimeters by 35 millimeters, comparable with commercial implantable devices yet overcoming the urgent critical issues related to reservoir refilling and powering.

Restoration of dystrophin expression in mice by suppressing a nonsense mutation through the incorporation of unnatural amino acids.

Approximately 11% of monogenic diseases involve nonsense mutations that are caused by premature termination codons. These codons can in principle be read-through via the site-specific incorporation of unnatural amino acids to generate full-length proteins with minimal loss of function. Here we report that aminoacyl-tRNA-synthase-tRNA pairs specific for the desired unnatural amino acids can be used to read through a nonsense mutation in the dystrophin gene. We show partial restoration of dystrophin expression in differentiated primary myoblasts (from a mdx mouse model and a patient with Duchenne muscular dystrophy), and restoration of muscle function in two mouse models: mdx mice, via viral delivery of the engineered tRNA-synthase-tRNA pair intraperitoneally or intramuscularly and of the associated unnatural amino acid intraperitoneally; and mice produced by crossing mdx mice and transgenic mice with a chromosomally integrated pair, via intraperitoneal delivery of the unnatural amino acid. The incorporation of unnatural amino acids to restore endogenous protein expression could be explored for therapeutic use.

Large, Anionic Liposomes Enable Targeted Intraperitoneal Delivery of a TLR 7/8 Agonist To Repolarize Ovarian Tumors' Microenvironment.

Ovarian cancer is the most lethal gynecological malignancy in the United States. Current standard of treatment includes surgical debulking and chemotherapy, such as cisplatin and paclitaxel. However, the patients' response rate for chemotherapy in ovarian cancer is not optimal, and they often develop chemoresistance and suffer from side effects. Current clinical trials make extensive use of immune checkpoint blockade (ICB) as a novel cancer immunotherapeutic strategy against ovarian tumors. However, the response rates for ICB antibodies remain limited to 10-20% of treated ovarian cancer patients despite the success of this approach in melanoma, renal, head and neck, and nonsmall cell lung cancers. This lack of efficacy is often attributed to the "cold" immune status of ovarian tumors, as these tumors often have a low number of tumor-infiltrating lymphocytes (TILs) but a high number of suppressive immune cells, including tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), or regulatory T cells (Tregs). Repolarizing TAMs could be a promising strategy to reshape the tumor immune microenvironment and promote antitumor activity when combined with ICBs. Toll-like receptor (TLR) 7 and 8 agonists, such as imiquimod and resiquimod, are potent immunostimulatory molecules with potential to repolarize macrophages. However, these small molecules have poor pharmacokinetic profiles and can induce severe side effects when administered systemically. Previously, our group demonstrated that various large, anionic nanomaterials (silica, PLGA, and polystyrene) specifically target TAMs when administered intraperitoneally (IP) to ovarian tumor-bearing mice. In the present study, we demonstrate that large, anionic liposomes administered IP also efficiently localize to TAMs and can be used to target the delivery of resiquimod. Resiquimod delivered in this targeted fashion promoted activation of M1 macrophages and T cell infiltration, while reducing the percentage of Tregs in the tumor microenvironment. Finally, liposome-formulated resiquimod significantly enhanced the efficacy of PD1 blockade against syngeneic ovarian tumors. We anticipate that further optimization of our liposomal delivery strategy can generate a clinically relevant strategy for more effective and safer immunotherapy for ovarian cancer patients.

Effects of alcohol on brain oxygenation and brain hypoxia induced by intravenous heroin

Alcohol is the most commonly used psychoactive drug, often taken in conjunction with opioid drugs. Since both alcohol and opioids can induce CNS depression, it is often assumed that alcohol potentiates the known hypoxic effects of opioid drugs. To address this supposition, we used oxygen sensors to examine the effects of alcohol on brain oxygenation and hypoxic responses induced by intravenous heroin in awake, freely moving rats. To eliminate robust sensory effects of alcohol following its oral or intraperitoneal delivery, alcohol was administered directly into the stomach via chronically implanted intragastric catheters at human relevant doses. Alcohol delivered at a 0.5 g/kg dose did not affect brain oxygen levels, except for a weak transient increase during drug delivery. This phasic oxygen increase was stronger at a 2.0 g/kg alcohol dose and followed by a weaker tonic increase. Since alcohol absorption from intragastric delivery is much slower and more prolonged than with intraperitoneal or intravenous injections, the rapid rise of brain oxygen levels suggests that alcohol has a direct action on sensory afferents in the stomach well before the drug physically reaches brain tissue via circulation. Despite slow tonic increases in brain oxygen, alcohol at the 2.0 g/kg dose strongly potentiates heroin-induced oxygen responses, increasing both the magnitude and duration of oxygen decrease. Therefore, under the influence of alcohol, the use of opioid drugs becomes much more dangerous, increasing brain hypoxia and enhancing the probability of serious health complications, including coma and death.

Hyperthermic Intraperitoneal Chemotherapy: A Critical Review

Simple SummaryPatients with cancer of the digestive system or ovarian cancer are at risk of developing peritoneal metastases (PM). In some patients with PM, surgery followed by intraperitoneal (IP) chemotherapy has emerged as a valid treatment option. The addition of hyperthermia is thought to further enhance the efficacy of IP chemotherapy. However, the results of recent clinical trials in large bowel cancer have put into question the use of hyperthermic intraperitoneal chemotherapy (HIPEC). Here, we review the rationale and current results of HIPEC for PM and propose a roadmap to further progress.With increasing awareness amongst physicians and improved radiological imaging techniques, the peritoneal cavity is increasingly recognized as an important metastatic site in various malignancies. Prognosis of these patients is usually poor as traditional treatment including surgical resection or systemic treatment is relatively ineffective. Intraperitoneal delivery of chemotherapeutic agents is thought to be an attractive alternative as this results in high tumor tissue concentrations with limited systemic exposure. The addition of hyperthermia aims to potentiate the anti-tumor effects of chemotherapy, resulting in the concept of heated intraperitoneal chemotherapy (HIPEC) for the treatment of peritoneal metastases as it was developed about 3 decades ago. With increasing experience, HIPEC has become a safe and accepted treatment offered in many centers around the world. However, standardization of the technique has been poor and results from clinical trials have been equivocal. As a result, the true value of HIPEC in the treatment of peritoneal metastases remains a matter of debate. The current review aims to provide a critical overview of the theoretical concept and preclinical and clinical study results, to outline areas of persisting uncertainty, and to propose a framework to better define the role of HIPEC in the treatment of peritoneal malignancies.

High-Efficient Production of Adipose-Derived Stem Cell (ADSC) Secretome Through Maturation Process and Its Non-scarring Wound Healing Applications

Recently, the stem cell-derived secretome, which is the set of proteins expressed by stem cells and secreted into the extracellular space, has been demonstrated as a critical contributor for tissue repair. In this study, we have produced two sets of high concentration secretomes from adipose-derived mesenchymal stem cells (ADSCs) that contain bovine serum or free of exogenous molecules. Through proteomic analysis, we elucidated that proteins related to extracellular matrix organization and growth factor-related proteins are highly secreted by ADSCs. Additionally, the application of ADSC secretome to full skin defect showed accelerated wound closure, enhanced angiogenic response, and complete regeneration of epithelial gaps. Furthermore, the ADSC secretome was capable of reducing scar formation. Finally, we show high-dose injection of ADSC secretome via intraperitoneal or transdermal delivery demonstrated no detectable pathological conditions in various tissues/organs, which supports the notion that ADSC secretome can be safely utilized for tissue repair and regeneration.

Calcium Carbonate Microparticles as Carriers of 224Ra: Impact of Specific Activity in Mice with Intraperitoneal Ovarian Cancer.

Patients with advanced-stage ovarian cancer face a poor prognosis because of recurrent peritoneal cavity metastases following surgery and chemotherapy. Alpha-emitters may enable the efficient treatment of such disseminated diseases because of their short range and highly energetic radiation. Radium-224 is a candidate α-emitter due to its convenient 3.6-day half-life, with more than 90% of the decay energy originating from α-particles. However, its inherent skeletal accumulation must be overcome to facilitate intraperitoneal delivery of the radiation dose. Therefore, 224Ra-labeled CaCO3 microparticles have been developed. The antitumor effect of CaCO3 microparticles as a carrier for 224Ra was investigated, with an emphasis on the ratio of activity to mass dose of CaCO3, that is, specific activity. Nude athymic mice were inoculated intraperitoneally with human ovarian cancer cells (ES-2) and treated with a single intraperitoneal injection of 224Ra-labeled CaCO3 microparticles with varying combinations of mass and activity dose, or cationic 224Ra in solution. Survival and ascites volume at sacrifice were evaluated. Significant therapeutic effect was achieved for all tested specific activities ranging from 0.4 to 4.6 kBq/mg. Although treatment with a mean activity dose of 1305 kBq/kg of cationic 224Ra prolonged the survival compared with the control, equivalent median survival could be achieved with 224Ra-labeled microparticles with a mean dose of only 420 kBq/kg. The best outcome was achieved with the highest specific activities (2.6 and 4.6 kBq/mg). Radium-224-labeled CaCO3 microparticles present a promising therapy against cancer dissemination in body cavities.

Assessment of workplace environmental contamination and occupational exposure to cisplatin and doxorubicin aerosols during electrostatic pressurized intraperitoneal aerosol chemotherapy

BackgroundElectrostatic precipitation pressurized intraperitoneal aerosol chemotherapy (ePIPAC) is a novel approach for intraperitoneal drug delivery. As ePIPAC using cisplatin and doxorubicin is performed in an operating room, the challenge is to safely deliver the chemotherapeutic aerosol intraperitoneally while preventing exposure to healthcare workers. The objective of this study was to describe cisplatin and doxorubicin workplace environmental contamination and healthcare worker exposure during ePIPAC. MethodsAntineoplastic drugs concentrations of cisplatin and doxorubicin were measured in wipe samples from the operating room, and urine samples were collected from healthcare workers. The air samples were collected in order to detect Cisplatin contamination. Cisplatin was analysed by inductively coupled plasma–mass spectrometry and doxorubicin by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry. ResultsNo trace of cisplatin was found in the air. Cisplatin and doxorubicin were detected on the operating room floor, surfaces, devices and personal protective equipment even after a cleaning protocol. No traces of cisplatin or doxorubicin were found in the urine samples. ConclusionIn this study, no internal contamination was found in the ePIPAC surgical team even after implementing two successive ePIPAC procedures. These results showed the effectiveness of the individual and collective protective measures applied. However, the cleaning procedure during ePIPAC should be respected to limit environmental exposure to chemotherapy to cisplatin and doxorubicin during ePIPAC.

Metronomic 5-Fluorouracil Delivery Primes Skeletal Muscle for Myopathy but Does Not Cause Cachexia.

Skeletal myopathy encompasses both atrophy and dysfunction and is a prominent event in cancer and chemotherapy-induced cachexia. Here, we investigate the effects of a chemotherapeutic agent, 5-fluorouracil (5FU), on skeletal muscle mass and function, and whether small-molecule therapeutic candidate, BGP-15, could be protective against the chemotoxic challenge exerted by 5FU. Additionally, we explore the molecular signature of 5FU treatment. Male Balb/c mice received metronomic tri-weekly intraperitoneal delivery of 5FU (23 mg/kg), with and without BGP-15 (15 mg/kg), 6 times in total over a 15 day treatment period. We demonstrated that neither 5FU, nor 5FU combined with BGP-15, affected body composition indices, skeletal muscle mass or function. Adjuvant BGP-15 treatment did, however, prevent the 5FU-induced phosphorylation of p38 MAPK and p65 NF-B subunit, signalling pathways involved in cell stress and inflammatory signalling, respectively. This as associated with mitoprotection. 5FU reduced the expression of the key cytoskeletal proteins, desmin and dystrophin, which was not prevented by BGP-15. Combined, these data show that metronomic delivery of 5FU does not elicit physiological consequences to skeletal muscle mass and function but is implicit in priming skeletal muscle with a molecular signature for myopathy. BGP-15 has modest protective efficacy against the molecular changes induced by 5FU.

Artificial Pancreas: In Silico Study Shows No Need of Meal Announcement and Improved Time in Range of Glucose With Intraperitoneal vs. Subcutaneous Insulin Delivery

Contemporary Artificial Pancreas (AP) consists of a subcutaneous (SC) glucose sensor, a SC insulin pump and a control algorithm. Even the most advanced systems are far from optimal, in particular due to the non-physiologic nature of SC route. While SC insulin delivery is convenient and minimally invasive, it introduces delays to insulin action that make tight control difficult, particularly during meals. In addition frequent patient interventions are needed, e.g., at mealtime. The intraperitoneal (IP) insulin delivery could address this major challenge since it exhibits a faster pharmacokinetics/pharmacodynamics, hence making easier to quickly respond to glycemic disturbances. A 1-day hospital closed-loop study has shown significant improvements of IP glucose control vs SC AP, and that meal announcement is not necessary. However, the IP AP has not been tested in more realistic everyday life conditions. In this work we have performed an in silico study of 14 days of an IP AP by using the UVA/Padova simulator which includes intra- and inter-day variability of insulin sensitivity and several real life scenarios. We show superiority of IP AP vs SC AP in terms of quality of glucose control (time in range 87% IP vs 80% SC) without the need of a meal announcement.

Abstract PO-033: Papaverine derivative smv-32 alleviates tumor hypoxia and radiosensitizes tumors by inhibiting mitochondrial metabolism

Abstract Radiation therapy is a standard type of treatment modality used to achieve local control in more than 50% of all cancer patients. However, tumor hypoxia reduces the effectiveness of radiation therapy by limiting the biologically effective dose. We identified that FDA-approved phosphodiesterase 10A (PDE10A) inhibitor papaverine (PPV) has an off-target effect inhibiting mitochondrial oxygen consumption (OCR) leading to acute reduction of tumor hypoxia and significant radiosensitization of model tumors. Our data suggests that PDE10A does not contribute to the radiosensitizing effect. Based on PPV’s structure, we used biomedicinal chemistry approach to engineer its novel derivative SMV-32 with reduced PDE10A inhibition. We used Seahorse metabolic flux analyzer to determine the effect of PPV and SMV-32 on mitochondrial OCR in vitro. Near-infrared optical spectroscopy and pODD-luciferase in vivo reporter system was used for pharmacodynamics analyses and dose response evaluation. Local radiation therapy was delivered using Small Animal Radiation Research Platform (SARRP). We compared intraperitoneal (IP) and intravenous (IV) delivery and optimized dosing using pODD luciferase reporter system. SMV-32 showed superior OCR inhibition in vitro and enhanced hypoxia reduction in vivo compared to PPV. A single clinically relevant dose of PPV or SMV-32 significantly reduced the hypoxic fractions of heterotopic and orthotopic tumors in mice and sensitized the tumors to radiation therapy. PPV and SMV-32 appear to be ideal candidates for clinical radiosensitization. PPV is already in phase I clinical trial for treatment of non-small cell lung cancer combined with stereotactic body radiation therapy. Citation Format: Martin Benej, Jinghai Wu, McKenzie Kreamer, Sandip Vibhute, Ioanna Papandreou, Nicholas C. Denko. Papaverine derivative smv-32 alleviates tumor hypoxia and radiosensitizes tumors by inhibiting mitochondrial metabolism [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-033.

Polycation fluorination improves intraperitoneal siRNA delivery in metastatic pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a growing medical problem associated with extensive metastasis and high mortality. Intraperitoneal (IP) administration of therapeutics promises to help the treatment of cancers originated from organs in the peritoneal cavity. In this study, we evaluated how physicochemical properties of self-assembled polycation/siRNA nanoparticles affect their IP delivery efficacy in an orthotopic PDAC model. We have examined the effect of covalent polycation modification with lipophobic and hydrophobic tetrafluoro-p-toluic acid (TFTA), hydrophobic cholesterol, and hydrophilic poly(ethylene glycol) respectively. The surface charge of the three different nanoparticles was also modulated by coating the surface with serum albumin. We found that positively charged fluorine-containing particles with lipophobic properties based on a mixture of positively charged polymeric AMD3100 CXCR4 antagonist (PAMD) and PAMD modified with TFTA (mPAMD-TFTA)/siRNA displayed the best cell uptake and transfection efficacy in vitro. Biodistribution evaluation of the nanoparticles in a syngeneic orthotopic PDAC model revealed that the fluorine-containing formulation also achieved the highest PDAC tumor accumulation after IP administration. With a combination of CXCR4 inhibition by PAMD and PLK1 downregulation by siRNA, the treatment with mPAMD-TFTA/siPLK1 showed significant inhibition of both primary and metastatic PDAC tumors. Overall, our study provides insights into and guides the design of the nanoparticles for improved IP delivery of siRNA in PDAC.

Experimental evaluation of icodextrin delivery as pressurized aerosol (PIPAC): Antiadhesive and cytotoxic effects

BackgroundIcodextrin (IDX) is an antiadhesive polymer that can be used as a carrier solution for intraperitoneal (IP) delivery of chemotherapeutic drugs. MethodsWe investigated the suitability of IDX solution as a carrier of Cisplatin and Doxorubicin for delivery as pressurized intraperitoneal aerosol chemotherapy (PIPAC). We examined the sprayability of IDX, the aerosol characteristics, the stability of the molecule after aerosolization, the effects of IDX on the adhesion of MKN45 human gastric cancer cells, the synergistic effect of aerosolized IDX with Cisplatin and Doxorubicin, and the chemical stability of IDX, Cisplatin, and Doxorubicin in combination. ResultsDelivery of IDX as PIPAC is feasible with no particular restrictions. The median droplet size of 35.7 μm did not change at increasing concentrations. IDX withstood the shear forces applied by the nebulizer and remained stable after aerosolization (ANOVA, p = 0.97). IDX did not impair the cytotoxic effects of Cisplatin and Doxorubicin (ns). IDX had a significant antiadhesive impact alone (p < 0.03) and in combination with Cisplatin and Doxorubicin (p < 0.02). IDX as a carrier for Cisplatin and Doxorubicin remained stable at 4 °C for three months and did not cause degradation of those two substances. ConclusionThe proposed combination takes advantage of the antiadhesive properties of IDX, the cytotoxic effect of Cisplatin and Doxorubicin, and an advanced drug delivery system.

History of intraperitoneal platinum drug delivery for ovarian cancer and its future applications

Intraperitoneal (IP) delivery of cisplatin was developed in the 1970s based on a strong pharmacologic rationale and rodent models. Its advantage over intravenous (IV) administration was supported initially by observational studies in treating recurrent ovarian cancer and eventually by better outcomes from IP vs. IV cisplatin in randomized studies in patients undergoing optimal surgical debulking at diagnosis. In the past two decades, with the introduction of novel anticancer interventions (such as taxanes, bevacizumab, inhibitors of DNA repair, and immune check point inhibitors), advantages of IP drug delivery are less clear and concerns are raised on cisplatin's therapeutic index. The discovery of BRCA genes and their key role in DNA repair, on the other hand, have strengthened the rationale for IP drug delivery: high grade serous cancers arising in the Mullerian epithelium in association with hereditary or somatic BRCA function inactivation are linked to peritoneal spread of cells that - while initially sensitive - are prone to emergence of platinum resistance. Therefore, selection of patients based on genomic features and focusing on the better tolerated IP carboplatin are ongoing. Recent examples of leveraging the peritoneal route include (1) targeting the cell membrane copper transport receptor - that is shared by platinums - by the combination of the proteasome inhibitor bortezomib and IP carboplatin; and (2) enhancing IP 5-fluoro-2-deoxyuridine cytotoxicity when coupled with PARP inhibition.

Enhanced intraperitoneal delivery of charged, aerosolized curcumin nanoparticles by electrostatic precipitation.

Aims: To investigate the potential of curcumin-loaded polylactic-co-glycolic acid nanoparticles (CUR-PLGA-NPs), alone and with electrostatic precipitation, for improving tissue uptake during pressurized intraperitoneal aerosol chemotherapy (PIPAC). Methods: Positively and negatively charged CUR-PLGA-NPs were delivered as PIPAC into inverted bovine urinary bladders exvivo. The experiment was repeated with the additional use of electrostatic precipitation pressurized intraperitoneal aerosol chemotherapy (electrostatic PIPAC). Results: Positively charged CUR-PLGA-NPs increased depth of tissue penetration by 81.5% and tissue concentration by 80%. Electrostatic precipitation further improved the uptake of positively charged CUR-PLGA-NPs by 41.8%. Conclusion: The combination of positive charge and electrostatic precipitation have significant potential to improve tissue uptake of nanoparticles during intraperitoneal chemotherapy.

DIPG-42. TOWARD MULTIMODALITY THERAPY FOR DIPG/DMG: DEVELOPMENT AND INVESTIGATION OF CRANIOSPINAL IRRADIATION AND CONVECTION-ENHANCED DELIVERY PDX MODELS

BACKGROUNDDiffuse intrinsic pontine glioma (DIPG) and diffuse midline glioma (DMG) are metastatic diseases, as demonstrated by early convection-enhanced delivery (CED) clinical trials in which prolonged local tumor control can sometimes be achieved, but fatal disseminated disease then develops. We hypothesize that improvements in treatment of both focal disease and the entire neuraxis are necessary for long-term survival, and patient-derived xenograft (PDX) models can help advance these efforts.METHODSWe used a BT245 murine orthotopic DIPG PDX model for this work. We developed a protocol and specialized platform to deliver craniospinal irradiation (CSI) with a pontine boost. We separately compared intratumoral drug concentration by CED and intraperitoneal delivery. In our CED model, mice receive gemcitabine 60 ug x1 in 15 ul at 0.5 ul/minute through a stepped catheter design with silica tubing extending 2mm beyond a 27G needle.RESULTSMice receiving CSI (4 Gy x2d) plus boost (4 Gy x2d) showed minimal spinal and brain leptomeningeal metastatic disease by bioluminescence, MRI, and pathology compared to mice receiving radiation to the pons only (4 Gy x4d) or no radiation. CED achieved an intratumoral gemcitabine concentration 50-fold greater than intraperitoneal dosing when controlled for dose.CONCLUSIONSIn a DIPG PDX model, CSI+boost minimizes tumor dissemination compared to focal radiation, and CED achieves clinically significant improvements in intratumoral chemotherapy concentration compared to systemic delivery. Adding these modalities to current treatment could improve both focal and metastatic tumor control, leading to meaningful improvements in survival.

A Novel Cerebroprotein Hydrolysate, CH1, Ameliorates Chronic Focal Cerebral Ischemia Injury by Promoting White Matter Integrity via the Shh/Ptch-1/Gli-1 Signaling Pathway.

PurposeStrokes are devastating as there are no current therapies to prevent long-term neurological deficits. Previous studies reported that cerebroprotein hydrolysate (CH) plays a role in neuronal protection in acute phase after ischemic stroke, while the long-term effects of CH upon brain plasticity and neurological outcomes after stroke are still uncertain. To address these gaps, we assessed the effect of a new cerebroprotein hydrolysate, CH1, on long-term gray and white matter integrity as well as axonal plasticity in the late phase after ischemic stroke and the potential mechanisms.MethodsAdult male mice were subjected to permanent distal middle cerebral artery occlusion (dMCAO), followed by daily intraperitoneal injection of CH1 for 14 days. Motor function was measured weekly through behavioral neurological evaluations. Gray matter intensity and white matter intensity were examined by immunofluorescence staining. The sonic hedgehog (Shh) inhibitor cyclopamine (CYC) was injected to determine the involvement of the Shh pathway in the therapeutic effects of CH1.ResultsWe found that intraperitoneal delivery of CH1, compared to vehicle administration, significantly improved long-term neurological outcomes at various times and promoted neuronal viability at 14 days but not at 28 days after stroke. Importantly, CH1 mitigated stroke-induced white matter injury and facilitated axonal plasticity in the late stage after stroke.ConclusionThese results unveil a previously unappreciated role for CH in the repair of white matter and brain plasticity after stroke.

Tumor-mesoporous silica nanoparticle interactions following intraperitoneal delivery for targeting peritoneal metastasis

The use of intraperitoneal administration of nanoparticles has been reported to facilitate higher concentrations of nanoparticles in metastatic peritoneal tumors. While this strategy is appealing for limiting systemic exposure of nanocarrier delivered toxic cargoes and increasing nanoparticle concentrations in avascular peritoneal tumors, little is known about the mechanism of nanoparticle accumulation on tumor tissues and currently, no nanoparticle-based product has been approved for intraperitoneal delivery. Here, we investigated the nanoparticle-specific characteristics that led to increased peritoneal tumor accumulation using MCM-41 type mesoporous silica nanoparticles as our model system. We also investigated the components of the peritoneal tumor stroma that facilitated nanoparticle-tumor interaction. The tumor extracellular matrix is the main factor driving these interactions, specifically the interaction of nanoparticles with collagen. Upon disruption of the collagen matrix, nanoparticle accumulation was reduced by 50%. It is also notable that the incorporation of targeting ligands did not increase overall tumor accumulation in vivo while it significantly increased nanoparticle accumulation in vitro. The use of other particle chemistries did not grossly affect the tumor targetability, but additional concerns arose when those tested particles exhibited significant systemic exposure. Mesoporous silica nanoparticles are advantageous for intraperitoneal administration for the treatment of peritoneal metastasis due to their physical stability, tumor targetability, strong interaction with the collagen matrix, and extended peritoneal residence time. Maximizing nanoparticle interaction with the tumor extracellular matrix is critical for developing strategies to deliver emerging therapeutics for peritoneal cancer treatment using nanocarriers.

Lentivirus Mediated Pancreatic Beta-Cell-Specific Insulin Gene Therapy for STZ-Induced Diabetes

Autoimmune destruction of pancreatic beta cells is the characteristic feature of type 1 diabetes mellitus. Consequently, both short- and intermediate-acting insulin analogs are under development to compensate for the lack of endogenous insulin gene expression. Basal insulin is continuously released at low levels in response to hepatic glucose output, while post-prandial insulin is secreted in response to hyperglycemia following a meal. As an alternative to multiple daily injections of insulin, glucose-regulated insulin gene expression by gene therapy is under development to better endure postprandial glucose excursions. Controlled transcription and translation of proinsulin, presence of glucose-sensing machinery, prohormone convertase expression, and a regulated secretory pathway are the key features unique to pancreatic beta cells. To take advantage of these hallmarks, we generated a new lentiviral vector (LentiINS) with an insulin promoter driving expression of the proinsulin encoding cDNA to sustain pancreatic beta-cell-specific insulin gene expression. Intraperitoneal delivery of HIV-based LentiINS resulted in the lowering of fasting plasma glucose, improved glucose tolerance and prevented weight loss in streptozoticin (STZ)-induced diabetic Wistar rats. However, the combinatorial use of LentiINS and anti-inflammatory lentiviral vector (LentiVIP) gene therapy was required to increase serum insulin to a level sufficient to suppress non-fasting plasma glucose and diabetes-related inflammation.

Lipopolysaccharide-induced sepsis-like state compromises post-ischemic neurological recovery, brain tissue survival and remodeling via mechanisms involving microvascular thrombosis and brain T cell infiltration

Sepsis predisposes for poor stroke outcome. This association suggests that sepsis disturbs post-ischemic tissue survival and brain remodeling. To elucidate this link, we herein exposed mice to 30 min intraluminal middle cerebral artery occlusion (MCAO) and induced a sepsis-like state at 72 h post-ischemia by intraperitoneal delivery of Escherichia coli lipopolysaccharide (LPS; three doses of 0.1 or 1 mg/kg, separated by 6 h), a major component of the bacterium’s outer membrane. Neurological recovery, ischemic injury, brain remodeling and immune responses were evaluated over up to 56 days post-sepsis (dps) by behavioral tests, immunohistochemistry and flow cytometry. Delivery of 1 mg/kg but not 0.1 mg/kg LPS reduced rectal temperature over 48 h by up to 3.4 ± 3.1 °C, increased general and focal neurological deficits in the Clark score over 72 h and increased motor-coordination deficits in the tight rope test over up to 21 days. Notably, 1 mg/kg, but not 0.1 mg/kg LPS increased intercellular adhesion molecule-1 abundance on ischemic microvessels, increased microvascular thrombosis and increased patrolling monocyte and T cell infiltrates in ischemic brain tissue at 3 dps. Infarct volume was increased by 1 mg/kg, but not 0.1 mg/kg LPS at 3 dps (that is, 6 days post-MCAO), as was brain atrophy at 28 and 56 dps. Microglial activation in ischemic brain tissue, evaluated by morphology analysis of Iba-1 immunostainings, was transiently increased by 0.1 and 1 mg/kg LPS at 3 dps. Our data provide evidence that neurological recovery and brain remodeling are profoundly compromised in the ischemic brain post-sepsis as a consequence of cerebral thromboinflammation.