Clinical outcomes of colorectal neoplasm with positive resection margin after endoscopic submucosal dissection.

A positive resection margin after colorectal endoscopic submucosal dissection (ESD) is associated with an increased risk of recurrence. We aimed to identify the clinical significance of positive resection margins in colorectal neoplasms after ESD. We reviewed 632 patients who had en bloc colorectal ESD at two hospitals between 2015 and 2020. The recurrence rates and presence of residual tumor after surgery were evaluated. The rate of additional surgery after ESD and recurrence rate were significantly higher in patients with incomplete resection (n = 75) compared to patients with complete resection (n = 557). When focusing solely on non-invasive lesions, no significant differences in recurrence rates were observed between the groups with complete and incomplete resection (0.2% vs. 1.9%, p = 0.057). Among 84 patients with submucosal invasive carcinoma, 39 patients underwent additional surgery due to non-curative resection. Positive vertical margin and lymphovascular invasion were associated with residual tumor. Lymphovascular invasion was associated with lymph node metastasis. However, no residual tumor nor lymph node metastases were found in patients with only one unfavorable histological factor. In conclusion, a positive resection margin in non-invasive colorectal lesions, did not significantly impact the recurrence rate. Also, in T1 colorectal cancer with a positive vertical resection margin, salvage surgery can be considered in selected patients with additional risk factors.

Successful Transcatheter Arterial Embolization of Abdominal Wall Hematoma from the Left Deep Circumflex Iliac Artery after Abdominal Paracentesis in a Patient with Liver Cirrhosis: Case Report and Literature Review.

The occurrence of an abdominal wall hematoma caused by abdominal paracentesis in patients with liver cirrhosis is rare. This paper presents a case of an abdominal wall hematoma caused by abdominal paracentesis in a 67-year-old woman with liver cirrhosis with a review of the relevant literature. Two days prior, the patient underwent abdominal paracentesis for symptom relief for refractory ascites at a local clinic. Upon admission, a physical examination revealed purpuric patches with swelling and mild tenderness in the left lower quadrant of the abdominal wall. Abdominal computed tomography revealed advanced liver cirrhosis with splenomegaly, tortuous dilatation of the para-umbilical vein, a large volume of ascites, and a large acute hematoma at the left lower quadrant of the abdominal wall. An external iliac artery angiogram showed the extravasation of contrast media from the left deep circumflex iliac artery. Embolization of the target arterial branches using N-butyl-2-cyanoacrylate was then performed, and the bleeding was stopped. The final diagnosis was an abdominal wall hematoma from the left deep circumflex iliac artery after abdominal paracentesis in a patient with liver cirrhosis.

Cardioprotective Effects of PARP Inhibitors: A Re-Analysis of a Meta-Analysis and a Real-Word Data Analysis Using the FAERS Database.

Objective: This study aimed to assess the potential of PARP inhibitors to prevent cardiotoxicity. Methods: First, a re-analysis and update of a previously published study was conducted. Additional searches were conducted of the PubMed and Cochrane Central Register of Controlled Trials databases on 2 June 2023. After the selection process, the pooled odds ratio (OR) for cardiac adverse events (AEs) was calculated. Second, the FAERS database was examined for 10 frequently co-administered anticancer agents. The reporting odds ratio (ROR) was calculated based on the occurrence of cardiac AEs depending on the co-administration of PARP inhibitors. Results: Seven studies were selected for the meta-analysis. Although not statistically significant, co-administration of PARP inhibitors with chemotherapy/bevacizumab decreased the risk of cardiac AEs (Peto OR = 0.61; p = 0.36), while co-administration with antiandrogens increased the risk of cardiac AEs (Peto OR = 1.83; p = 0.18). A total of 19 cases of cardiac AEs were reported with co-administration of PARP inhibitors in the FAERS database. Co-administration of PARP inhibitors with chemotherapy/bevacizumab significantly decreased the risk of cardiac AEs (ROR = 0.352; 95% confidence interval (CI), 0.194-0.637). On the other hand, for antiandrogens co-administered with PARP inhibitors, the ROR was 3.496 (95% CI, 1.539-7.942). The ROR for immune checkpoint inhibitors co-administered with PARP inhibitors was 0.606 (95% CI, 0.151-2.432), indicating a non-significant effect on cardiac AEs. Conclusion: This study reports that PARP inhibitors show cardioprotective effects when used with conventional anticancer agents.

Cytochrome P450 Family 46 Subfamily A Member 1 Promotes the Progression of Colorectal Cancer by Inducing Tumor Cell Proliferation and Angiogenesis.

BACKGROUND/AIM: Cytochrome P450 family 46 subfamily A member 1 (CYP46A1) has been implicated in the development and progression of various cancers. This study aimed to analyze the expression of CYP46A1, examining its relationship with oncogenic behaviors, and determining its prognostic implications in colorectal cancer (CRC). MATERIALS AND METHODS: A total of 225 patients with CRC who underwent curative surgical resection were examined using paraffin-embedded tissue blocks and subjected to tumor-specific survival analysis. The expression of CYP46A1 was assessed in CRC tissues through reverse transcription-polymerase chain reaction, western blotting, and immunohistochemistry. The CRC cells' apoptosis, proliferation, angiogenesis, and lymphangiogenesis were analyzed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays, alongside immunohistochemical staining for Ki-67, CD34, and D2-40 antibodies. RESULTS: CYP46A1 expression was found to be up-regulated in CRC tissues compared to normal colorectal mucosa. Such expression was significantly associated with advanced stage, deeper tumor invasion, lymph node metastasis, distant metastasis, and decreased survival. Furthermore, the mean Ki-67 labeling index and microvessel density values in CYP46A1-positive tumors were significantly elevated compared to CYP46A1-negative tumors. However, there was no discernible correlation between CYP46A1 expression and either the apoptotic index or lymphatic vessel density value. CONCLUSION: CYP46A1 promotes CRC progression, specifically through the induction of tumor cell proliferation and angiogenesis. The insights provided may hold potential implications for future therapeutic interventions targeting CYP46A1.

Successful Simultaneous Treatment of Benign Stricture and Colonic Neoplasm Arising from Colonic Interposition after Esophagectomy: A Case Report.

Colonic interposition is the main procedure used in esophageal reconstruction. We report a rare case of simultaneous treatment of an anastomotic site stricture and a neoplasm in the interpositioned colon. A 69-year-old female visited our outpatient clinic with symptoms of progressive dysphagia for 1 year. At the age of 30 years, the patient underwent esophagectomy with retrosternal colonic interposition because of severe esophageal burns after chemical ingestion. Upper gastrointestinal endoscopy revealed stricture at the anastomosis site and a 10-mm flat elevated high-grade dysplasia in the interpositioned colon. First, through-the-scope balloon dilatation was performed for strictures. However, stenosis was observed during the second upper gastrointestinal endoscopy session. Therefore, a second session of through-the-scope balloon dilatation was performed, and simultaneously, endoscopic submucosal dissection was also successfully performed. After 2 months of follow-up, stenosis persisted; consequently, balloon dilatation was performed. No recurrence of neoplasm was confirmed endoscopically. Through-the-scope balloon dilatation of the stricture site and simultaneous endoscopic submucosal dissection of the neoplasm in the interpositioned colon were successfully performed.

Systemic γ-sarcoglycan AAV gene transfer results in dose-dependent correction of muscle deficits in the LGMD 2C/R5 mouse model.

Limb-girdle muscular dystrophy (LGMD) type 2C/R5 results from mutations in the γ-sarcoglycan (SGCG) gene and is characterized by muscle weakness and progressive wasting. Loss of functional γ-sarcoglycan protein in the dystrophin-associated protein complex destabilizes the sarcolemma, leading to eventual myofiber death. The SGCG knockout mouse (SGCG -/-) has clinical-pathological features that replicate the human disease, making it an ideal model for translational studies. We designed a self-complementary rAAVrh74 vector containing a codon-optimized human SGCG transgene driven by the muscle-specific MHCK7 promoter (SRP-9005) to investigate adeno-associated virus (AAV)-mediated SGCG gene transfer in SGCG -/- mice as proof of principle for LGMD 2C/R5. Gene transfer therapy resulted in widespread transgene expression in skeletal muscle and heart, improvements in muscle histopathology characterized by decreased central nuclei and fibrosis, and normalized fiber size. Histopathologic improvements were accompanied by functional improvements, including increased ambulation and force production and resistance to injury of the tibialis anterior and diaphragm muscles. This study demonstrates successful systemic delivery of the hSGCG transgene in SGCG -/- mice, with functional protein expression, reconstitution of the sarcoglycan complex, and corresponding physiological and functional improvements, which will help establish a minimal effective dose for translation of SRP-9005 gene transfer therapy in patients with LGMD 2C/R5.

The Gangwon Obesity and Metabolic Syndrome Study: Methods and Initial Baseline Data.

Background: The prevalence of obesity has been continuously increasing, especially in rural areas of South Korea. Therefore, it is important to examine various genetic, behavioral, and environmental factors associated with obesity in these rural areas. The Korean Society for the Study of Obesity commenced a community-based prospective cohort study of the Gangwon area called the Gangwon Obesity and Metabolic Syndrome (GOMS) study to investigate longitudinal changes in the status of obesity and its related factors. Methods: A total of 317 adults 40-69 years of age were recruited from Hongcheon and Inje districts, Gangwon province, as part of the first wave of this cohort study. Information on participants' demographic, behavioral, psychological, dietary, and environmental factors and past medical histories were collected by self-administered questionnaires and interviewer-administered questionnaires. Anthropometric measurements, blood tests, and a hand grip strength test were performed, and skin keratin and stool samples were collected. Among the 317 enrolled subjects, two participants who did not have anthropometric data were excluded from the data analyses, resulting in an inclusion of a total of 315 participants. Results: The mean age of the 315 participants in the GOMS initial baseline survey was 58.5 years old, 87 of them were men, and the mean body mass index was 24.7±3.7 kg/m2. Among all participants, 48.9% had hypertension, 21.4% had diabetes mellitus (DM), 55.6% had dyslipidemia, and 46.0% had metabolic syndrome (MS). Both the prevalence rates of DM and MS were significantly higher in men. Conclusion: The first baseline survey of the GOMS study was initiated, and a more detailed analysis of respondents' data is expected to be continued. Further follow-up and additional recruitment will allow the investigation of risk factors and the etiology of obesity and its comorbidities in rural areas of Gangwon province.

Poly(amine-co-ester) nanoparticles for effective Nogo-B knockdown in the liver.

Degradable poly(amine-co-ester) (PACE) terpolymers hold tremendous promise for siRNA delivery because these materials can be formulated into delivery vehicles with highly efficient siRNA encapsulation, providing effective knockdown with low toxicity. Here, we demonstrate that PACE nanoparticles (NPs) provide substantial protein knockdown in human embryonic kidney cells (HEK293) and hard-to-transfect primary human umbilical vein endothelial cells (HUVECs). After intravenous administration, NPs of solid PACE (sPACE)-synthesized with high monomer content of a hydrophobic lactone-accumulated in the liver and, to a lesser extent, in other tissues. Within the liver, a substantial fraction of sPACE NPs were phagocytosed by liver macrophages, while a smaller fraction of NPs accumulated in hepatic stellate cells and liver sinusoidal endothelial cells, suggesting that sPACE NPs could deliver siRNA to diverse cell populations within the liver. To test this hypothesis, we loaded sPACE NPs with siRNA designed to knockdown Nogo-B, a protein that has been implicated in the progression of alcoholic liver disease and liver fibrosis. These sPACE:siRNA NPs produced up to 60% Nogo-B protein suppression in the liver after systemic administration. We demonstrate that sPACE NPs can effectively deliver siRNA therapeutics to the liver to mediate protein knockdown in vivo.

Nanoparticle-mediated intratumoral inhibition of miR-21 for improved survival in glioblastoma.

Glioblastoma (GBM) is the most common and deadly form of malignant brain tumor in the United States, and current therapies fail to provide significant improvement in survival. Local delivery of nanoparticles is a promising therapeutic strategy that bypasses the blood-brain barrier, minimizes systemic toxicity, and enhances intracranial drug distribution and retention. Here, we developed nanoparticles loaded with agents that inhibit miR-21, an oncogenic microRNA (miRNA) that is strongly overexpressed in GBM compared to normal brain tissue. We synthesized, engineered, and characterized two different delivery systems. One was designed around an anti-miR-21 composed of RNA and employed a cationic poly(amine-co-ester) (PACE). The other was designed around an anti-miR-21 composed of peptide nucleic acid (PNA) and employed a block copolymer of poly(lactic acid) and hyperbranched polyglycerol (PLA-HPG). We show that both nanoparticle products facilitate efficient intracellular delivery and miR-21 suppression that leads to PTEN upregulation and apoptosis of human GBM cells. Further, when administered by convection-enhanced delivery (CED) to animals with intracranial gliomas, they both induced significant miR-21 knockdown and provided chemosensitization, resulting in improved survival when combined with chemotherapy. The challenges involved in optimizing the two delivery systems differed, and despite offering distinct advantages and limitations, results showed significant therapeutic efficacy with both methods of treatment. This study demonstrates the feasibility and promise of local administration of miR-21 inhibiting nanoparticles as an adjuvant therapy for GBM.

Clinical Importance of Antibiotic Regimen in Transrectal Ultrasound-Guided Prostate Biopsy: A Single Center Analysis of Nine Thousand Four Hundred Eighty-Seven Cases.

BACKGROUND: To evaluate the effectiveness of an antibiotic regimen for prostate biopsy by analyzing patients who were hospitalized because of complications after transrectal ultrasound-guided prostate biopsy. METHODS: We reviewed retrospectively the medical records of 10,339 patients who underwent transrectal ultrasound-guided prostate biopsy at our institution from May 2003 to April 2017. We excluded patients with low quality data. All patients underwent urine culture before transrectal ultrasound-guided prostate biopsy and received intravenous antibiotic agents 30-60 minutes before biopsy. Patients were either given prophylactic quinolone or cephalosporin (second or third generation). Clinicopathologic factors including patient age, antibiotic regimen, number of biopsy cores, body mass index, prostate specific antigen, prostate volume, and infection-related complications that required hospitalization were subsequently analyzed. RESULTS: A total of 9,487 patients were included in the final analysis, of whom 33 patients (0.35%) were hospitalized because of infection-related complications. Infection-related hospitalization rates were lower in patients who received cephalosporin (0.2%) than in patients who received quinolone (1.59%). At our institution, cephalosporin has been used predominantly to prevent post-biopsy infections since February 2013. Only five patients (0.12%) developed infection-related complications of the 3,863 patient who underwent transrectal ultrasound-guided prostate biopsy since February 2013. Multivariable analysis revealed that use of second- or third-generation cephalosporin was the only independent predictor of infection-related complications. CONCLUSION: Implementing an effective antibiotic prophylaxis regimen at our institution by using second- or third-generation cephalosporin could reduce infection-related complications after transrectal ultrasound-guided prostate biopsy.

Biodegradable PEG-poly(ω-pentadecalactone-co-p-dioxanone) nanoparticles for enhanced and sustained drug delivery to treat brain tumors.

Intracranial delivery of therapeutic agents is limited by penetration beyond the blood-brain barrier (BBB) and rapid metabolism of the drugs that are delivered. Convection-enhanced delivery (CED) of drug-loaded nanoparticles (NPs) provides for local administration, control of distribution, and sustained drug release. While some investigators have shown that repeated CED procedures are possible, longer periods of sustained release could eliminate the need for repeated infusions, which would enhance safety and translatability of the approach. Here, we demonstrate that nanoparticles formed from poly(ethylene glycol)-poly(ω-pentadecalactone-co-p-dioxanone) block copolymers [PEG-poly(PDL-co-DO)] are highly efficient nanocarriers that provide long-term release: small nanoparticles (less than 100 nm in diameter) continuously released a radiosensitizer (VE822) over a period of several weeks in vitro, provided widespread intracranial drug distribution during CED, and yielded significant drug retention within the brain for over 1 week. One advantage of PEG-poly(PDL-co-DO) nanoparticles is that hydrophobicity can be tuned by adjusting the ratio of hydrophobic PDL to hydrophilic DO monomers, thus making it possible to achieve a wide range of drug release rates and drug distribution profiles. When administered by CED to rats with intracranial RG2 tumors, and combined with a 5-day course of fractionated radiation therapy, VE822-loaded PEG-poly(PDL-co-DO) NPs significantly prolonged survival when compared to free VE822. Thus, PEG-poly(PDL-co-DO) NPs represent a new type of versatile nanocarrier system with potential for sustained intracranial delivery of therapeutic agents to treat brain tumors.

Effects of Nonsteroidal Anti-Inflammatory Drugs as Patient Controlled Analgesia on Early Bowel Function Recovery after Radical Cystectomy.

This study aimed to evaluate the effects of ketorolac, a commonly used non-steroidal anti-inflammatory drug (NSAID) as patient controlled intravenous infusion analgesia (PCIA) for the patients underwent radical cystectomy (RC) due to bladder cancer regarding post-operational indices of recovery. Total seventy patients who underwent radical cystectomy for the treatment of bladder cancer were included in the study. 35 patients received ketorolac as PCIA (NSAIDS group) and 35 patients had morphine infusion as PCIA (morphine group). Pain intensity, bowel function recovery and length of hospital stay were evaluated. Early postoperative complications were analyzed according to surgical types (robot RC vs. open RC). Demographics were similar between two groups. NSAIDS group showed a significant reduction in postoperative vomiting (p = 0.001), time to flatus (p = 0.028), time to first bowel movement (p = 0.001) and time to first clear liquid diet (p = 0.002) compared with morphine group. No statistically significant differences were observed between two groups regarding length of hospitalization, and postoperative complications. For 48 hours after RC, pain relief was slightly better in morphine group (p < 0.001). Both open RC and robot RC cases showed significantly better bowel function recovery with NSAIDS groups. Ketorolac as PCIA is relatively effective in pain management with better gastrointestinal recovery after RC.

Surface chemistry governs cellular tropism of nanoparticles in the brain.

Nanoparticles are of long-standing interest for the treatment of neurological diseases such as glioblastoma. Most past work focused on methods to introduce nanoparticles into the brain, suggesting that reaching the brain interstitium will be sufficient to ensure therapeutic efficacy. However, optimized nanoparticle design for drug delivery to the central nervous system is limited by our understanding of their cellular deposition in the brain. Here, we investigated the cellular fate of poly(lactic acid) nanoparticles presenting different surface chemistries, after administration by convection-enhanced delivery. We demonstrate that nanoparticles with 'stealth' properties mostly avoid internalization by all cell types, but internalization can be enhanced by functionalization with bio-adhesive end-groups. We also show that association rates measured in cultured cells predict the extent of internalization of nanoparticles in cell populations. Finally, evaluating therapeutic efficacy in an orthotopic model of glioblastoma highlights the need to balance significant uptake without inducing adverse toxicity.

Roles of Bcl-2 and caspase-9 and -3 in CD30-induced human eosinophil apoptosis.

BACKGROUND/PURPOSE: Activation of cell surface CD30 by immobilized anti-CD30 monoclonal antibodies (mAb) induces strong apoptosis in human eosinophils. This anti-CD30 mAb-induced eosinophil apoptosis is inhibited by the addition of inhibitors of p38, ERK1/2 mitogen-activated protein kinases, and phosphatidylinositol 3-kinase. However, there is little data investigating the role of Bcl-2 and caspases in eosinophil apoptosis induced by anti-CD30 mAb. We sought to determine whether anti-CD30 mAb induces human eosinophil apoptosis via Bcl-2 and caspase pathways. METHODS: Peripheral blood was drawn from 37 healthy volunteers. The CD30 expression on eosinophils was measured at various time points. Eosinophils were then cultured in plates precoated with anti-CD30 mAb (clone Ber-H8), isotype control immunoglobulin G1, interleukin (IL)-5, or dexamethasone. Western blot analysis was performed to determine the expression of Bcl-2, procaspase-8, -9, and -3, and caspase-8, -9, and -3 after cross-linking of CD30. Human eosinophils were also cultured in plates precoated with anti-CD30 mAb (clone Ber-H8) in the presence or absence of caspase-9 or -3 inhibitors. Eosinophil apoptosis was assessed using flow cytometry. RESULTS: The addition of anti-CD30 mAb significantly increased eosinophil apoptosis compared with controls. In western blot analysis, the addition of anti-CD30 mAb significantly decreased the expression of Bcl-2 and procaspase-9 and -3 and increased the expression of caspase-9 and -3. The addition of caspase-9 or -3 inhibitors decreased anti-CD30 mAb-induced human eosinophil apoptosis. Procaspase-8 or caspase-8 expression was not changed in response to various stimuli. CONCLUSION: Anti-CD30 mAb-induced human eosinophil apoptosis is likely to be mediated through Bcl-2 and caspase-9 and -3.

Nanomaterials for convection-enhanced delivery of agents to treat brain tumors.

Nanomaterials represent a promising and versatile platform for the delivery of therapeutics to the brain. Treatment of brain tumors has been a long-standing challenge in the field of neuro-oncology. The current standard of care - a multimodal approach of surgery, radiation and chemotherapy - yields only a modest therapeutic benefit for patients with malignant gliomas. A major obstacle for treatment is the failure to achieve sufficient delivery of therapeutics at the tumor site. Recent advances in local drug delivery techniques, along with the development of highly effective brain-penetrating nanocarriers, have significantly improved treatment and imaging of brain tumors in preclinical studies. The major advantage of this combined strategy is the ability to optimize local therapy, by maintaining an effective and sustained concentration of therapeutics in the brain with minimal systemic toxicity. This review highlights some of the latest developments, significant advancements and current challenges in local delivery of nanomaterials for the treatment of brain tumors.

Clinical Impact of Mixed Respiratory Viral Infection in Children with Adenoviral Infection.

BACKGROUND: Although adenovirus (ADV) infection occurs steadily all year round in Korea and the identification of respiratory viral coinfections has been increasing following the introduction of multiplex real-time polymerase chain reaction tests, the clinical impact of viral coinfection in children with ADV infection has rarely been reported. MATERIALS AND METHODS: Medical records of children diagnosed with ADV infection were retrospectively reviewed. The enrolled children were divided into two groups based on the identified respiratory viruses: ADV group and coinfection group. Clinical and laboratory parameters were compared between the two groups. RESULTS: In total, 105 children (60 males and 45 females) with a median age of 29 months (range: 0-131 months) diagnosed with an ADV infection were enrolled. Fever (99.0%) was by far the most frequent symptom, followed by respiratory (82.9%), and gastrointestinal (22.9%) symptoms. Upper and lower respiratory tract infections were diagnosed in 56 (53.3%), and 32 (30.5%) children, respectively. Five (4.8%) children received oxygen therapy, and no child died due to ADV infection. Coinfection was diagnosed in 32 (30.5%) children, with rhinovirus (46.9%), and respiratory syncytial virus (21.9%) being the most frequent. The proportions of children younger than 24 months (P <0.001), with underlying medical conditions (P = 0.020), and diagnosed with lower respiratory tract infection (P = 0.011) were significantly higher in the coinfection group than in the ADV group. In a multivariate analysis, only the younger age was significantly associated with coinfection (P <0.001). Although more children in the coinfection group received oxygen therapy (P = 0.029), the duration of fever and hospitalization was not significantly different between the two groups. CONCLUSION: Respiratory viral coinfection with ADV occurred more frequently in children younger than 24 months of age compared with children aged 24 months or older. Respiratory viral coinfection may increase the severity of ADV infection, however, appropriate therapy prevented prolonged hospitalization and poor prognosis due to coinfection.

Varicella with rapidly progressive hepatitis presenting with multiple hepatic nodules in a child with acute leukemia.

Abdominal pain may precede the characteristic varicella skin lesions in immunocompromised patients with visceral varicella. The absence of skin lesions may delay timely diagnosis and treatment of varicella for those patients. Furthermore, abdominal imaging findings to provide information to diagnose visceral varicella have rarely been reported. Varicella was diagnosed in a 5-year-old boy with acute lymphoblastic leukemia complaining of fever and abdominal pain followed by papulovesicular skin lesions. Later, the patient was found to have rapidly progressive acute hepatitis, and abdominal computed tomography showed multiple hypodense hepatic nodules. The patient was treated with intravenous acyclovir, intravenous immunoglobulin, and empirical antibiotic and antifungal therapy. However, his fever and abdominal pain persisted, and a laparoscopic liver biopsy was performed to differentiate other causes of the persisting symptoms. Eventually, the patient was diagnosed with visceral varicella based on histopathologic findings. In conclusion, visceral varicella should be considered in immunocompromised patients with abdominal pain and multiple hypodense hepatic nodules on abdominal imaging studies. However, bacteria, fungi, and tuberculosis can produce similar imaging findings; therefore, a biopsy may be necessary in patients not responding to antiviral therapy.

Distribution of polymer nanoparticles by convection-enhanced delivery to brain tumors.

Glioblastoma multiforme (GBM) is a fatal brain tumor characterized by infiltration beyond the margins of the main tumor mass and local recurrence after surgery. The blood-brain barrier (BBB) poses the most significant hurdle to brain tumor treatment. Convection-enhanced delivery (CED) allows for local administration of agents, overcoming the restrictions of the BBB. Recently, polymer nanoparticles have been demonstrated to penetrate readily through the healthy brain when delivered by CED, and size has been shown to be a critical factor for nanoparticle penetration. Because these brain-penetrating nanoparticles (BPNPs) have high potential for treatment of intracranial tumors since they offer the potential for cell targeting and controlled drug release after administration, here we investigated the intratumoral CED infusions of PLGA BPNPs in animals bearing either U87 or RG2 intracranial tumors. We demonstrate that the overall volume of distribution of these BPNPs was similar to that observed in healthy brains; however, the presence of tumors resulted in asymmetric and heterogeneous distribution patterns, with substantial leakage into the peritumoral tissue. Together, our results suggest that CED of BPNPs should be optimized by accounting for tumor geometry, in terms of location, size and presence of necrotic regions, to determine the ideal infusion site and parameters for individual tumors.

Cellular distribution of injected PLGA-nanoparticles in the liver.

The cellular fate of nanoparticles in the liver is not fully understood. Because the effectiveness and safety of nanoparticles in liver therapy depends on targeting nanoparticles to the right cell populations, this study aimed to determine a relative distribution of PLGA-nanoparticles (sizes 271±1.4 nm) among liver cells in vivo. We found that Kupffer cells were the major cells that took up nanoparticles, followed by liver sinusoidal endothelial cells and hepatic stellate cells. Nanoparticles were found in only 7% of hepatocytes. Depletion of Kupffer cells by clodronate liposomes increased nanoparticle retention in liver sinusoidal endothelial cells and hepatic stellate cells, but not in hepatocytes. It is importantly suggested that studies of drug-loaded nanoparticle delivery to the liver have to demonstrate not only uptake of nanoparticles by the target cell type but also non-uptake by other cell types to assess their effect as well as ensure their safety.

Cell penetrating peptide-modified poly(lactic-co-glycolic acid) nanoparticles with enhanced cell internalization.

The surface modification of nanoparticles (NPs) can enhance the intracellular delivery of drugs, proteins, and genetic agents. Here we studied the effect of different surface ligands, including cell penetrating peptides (CPPs), on the cell binding and internalization of poly(lactic-co-glycolic) (PLGA) NPs. Relative to unmodified NPs, we observed that surface-modified NPs greatly enhanced cell internalization. Using one CPP, MPG (unabbreviated notation), that achieved the highest degree of internalization at both low and high surface modification densities, we evaluated the effect of two different NP surface chemistries on cell internalization. After 2h, avidin-MPG NPs enhanced cellular internalization by 5 to 26-fold relative to DSPE-MPG NP formulations. Yet, despite a 5-fold increase in MPG density on DSPE compared to Avidin NPs, both formulations resulted in similar internalization levels (48 and 64-fold, respectively) after 24h. Regardless of surface modification, all NPs were internalized through an energy-dependent, clathrin-mediated process, and became dispersed throughout the cell. Overall both Avidin- and DSPE-CPP modified NPs significantly increased internalization and offer promising delivery options for applications in which internalization presents challenges to efficacious delivery.