In situ identification and G4-PPI-His-Mal-dendrimer-induced reduction of early-stage amyloid aggregates in Alzheimer's disease transgenic mice using synchrotron-based infrared imaging.

Amyloid plaques composed of Aß amyloid peptides and neurofibrillary tangles are a pathological hallmark of Alzheimer Disease. In situ identification of early-stage amyloid aggregates in Alzheimer's disease is relevant for their importance as potential targets for effective drugs. Synchrotron-based infrared imaging is here used to identify early-stage oligomeric/granular aggregated amyloid species in situ in the brain of APP/PS1 transgenic mice for the first time. Also, APP/PS1 mice show fibrillary aggregates at 6 and 12 months. A significant decreased burden of early-stage aggregates and fibrillary aggregates is obtained following treatment with poly(propylene imine) dendrimers with histidine-maltose shell (a neurodegenerative protector) in 6-month-old APP/PS1 mice, thus demonstrating their putative therapeutic properties of in AD models. Identification, localization, and characterization using infrared imaging of these non-fibrillary species in the cerebral cortex at early stages of AD progression in transgenic mice point to their relevance as putative pharmacological targets. No less important, early detection of these structures may be useful in the search for markers for non-invasive diagnostic techniques.

Brefeldin A delivery nanomicelles in hepatocellular carcinoma therapy: Characterization, cytotoxic evaluation in vitro, and antitumor efficiency in vivo.

Hepatocellular carcinoma (HCC) is one of the major cancers with high mortality rate. Traditional drugs used in clinic are usually limited by the drug resistance and side effect and novel agents are still needed. Macrolide brefeldin A (BFA) is a well-known lead compound in cancer chemotherapy, however, with poor solubility and instability. In this study, to overcome these disadvantages, BFA was encapsulated in mixed nanomicelles based on TPGS and F127 copolymers (M-BFA). M-BFA was conferred high solubility, colloidal stability, and capability of sustained release of intact BFA. In vitro, M-BFA markedly inhibited the proliferation, induced G0/G1 phase arrest, and caspase-dependent apoptosis in human liver carcinoma HepG2 cells. Moreover, M-BFA also induced autophagic cell death via Akt/mTOR and ERK pathways. In HepG2 tumor-bearing xenograft mice, indocyanine green (ICG) as a fluorescent probe loaded in M-BFA distributed to the tumor tissue rapidly, prolonged the blood circulation, and improved the tumor accumulation capacity. More importantly, M-BFA (10 mg/kg) dramatically delayed the tumor progression and induced extensive necrosis of the tumor tissues. Taken together, the present work suggests that M-BFA has promising potential in HCC therapy.

[Influence of unmodified and modified sutures on experimental abdominal adhesive process]. / Éksperimental'naia otsenka spaechnogo protsessa v briushnoi polosti pri ispol'zovanii nemodifitsirovannogo shovnogo materiala i modifitsirovannogo geparinom.

OBJECTIVE: Experimental assessment of the effect of modified and unmodified surgical suture material on abdominal adhesive process. MATERIAL AND METHODS: The study was performed on male rats of the Wistar subpopulation. There were 5 animals in each group. In all animals, midline abdominal incision was followed by suturing the parietal peritoneum with modified and unmodified suture material. All animals were euthanized with carbon dioxide vapors in 14 days after surgery. Macro- and microscopic assessment of severity of abdominal adhesive process was carried out. Two types of preparation of excised complexes 'peritoneum-suture material-adhesion' were applied for histological examination: paraffin sections and embedding in epoxy resin. Specimens were stained by Van Gieson and with methylene blue solution. Histological specimens were examined using Axio Imager A1 light microscope (Zeiss, Germany). RESULTS: Polypropylene filaments result extensive adhesions occupying about 75% of the area. Adhesions have a dense structure with signs of vascularization. Modification of suture material with solution of polyhydroxybutyrate/hydroxyvalerate and heparin reduce severity of adhesions. The use of modified suture material was followed by adhesions with more loose structure, no signs of vascularization. Adhesions occupied less than 25% of the area. Histological examination of excised complexes 'peritoneum-suture material-adhesion' revealed accumulation of inflammatory cells around the unmodified suture material, while there were no signs of tissue inflammatory process around the modified sutures. CONCLUSION: Application of polyhydroxybutyrate/hydroxyvalerate and heparin on the surface of surgical sutures is an effective method for prevention of abdominal adhesions.

A biodegradable CO2-based polymeric antitumor nanodrug via a one-pot surfactant- and solvent-free miniemulsion preparation.

In the present study, low molecular weight poly(propylene carbonate) (PPC, Mn = 3500), a biodegradable liquid polymer easily prepared from carbon dioxide (CO2), was modified into poly(propylene carbonate)diacrylate (PPC-DA) by acylation, and methoxy poly(ethylene glycol) (mPEG) was modified into methoxy poly(ethylene glycol) acrylate (mPEG-A). Using PPC-DA as the dispersant to dissolve hydrophobic doxorubicin (DOX) and the initiator, and with mPEG-A as the co-monomer and polymerisable surfactant, a biodegradable nanodrug with excellent biocompatibility was prepared by shear emulsification polymerization without surfactants or organic solvent residues. The nanodrug can be efficiently endocytosed by tumor cells and can rapidly release doxorubicin triggered by the acidic endosomal pH. As evidenced by experiments in tumor-bearing mice, such a nanodrug is stealthy during blood circulation, and targets tumor sites with high efficiency. Moreover, this nanodrug is more effective and less toxic than free doxorubicin. This study provides a green and versatile approach for preparing biodegradable nanodrugs via a simple and efficient process. Moreover, this study extends the applications of CO2 based polymers in the biomedical field, promoting the development of CO2 polymerization fixation.

The use of synthetic mesh in contaminated and infected abdominal wall repairs: challenging the dogma-A long-term prospective clinical trial.

BACKGROUND: Abdominal wall reconstruction in patients presenting with enteric fistulas and mesh infection is challenging. There is a consensus that synthetic mesh must be avoided in infected operations, and the alternatives to using synthetic mesh, such as component separation techniques and biologic mesh, present disappointing results with expressive wound infection and hernia recurrence rates. METHODS: A prospective clinical trial designed to evaluate the short- and long-term outcomes of 40 patients submitted to elective abdominal wall repair with synthetic mesh in the dirty-infected setting, and compared to a cohort of 40 patients submitted to clean ventral hernia repairs. Patients in both groups were submitted to a single-staged repair using onlay polypropylene mesh reinforcement. RESULTS: Groups' characteristics were similar. There were 13 (32.5%) surgical site occurrences in the infected mesh (IM) group, compared to 11 (27.5%) in the clean-control (CC) group, p = 0.626. The 30-day surgical site infection rate was 15% for the IM group vs. 10% for the CC cases, p = 0.499. One patient required a complete mesh removal in each group. The mean overall follow-up was 50.2 ± 14.8 months, with 36 patients in the IM group and 38 clean-controls completing a follow-up of 36 months. There was one hernia recurrence (4.2%) in the IM group and no recurrences in the CC group. CONCLUSION: We demonstrated that using polypropylene mesh in the infected setting presented similar outcomes to clean repairs. The use of synthetic mesh in the onlay position resulted in a safe and durable abdominal wall reconstruction. TRIAL REGISTRATION: Study registered at Plataforma Brasil (plataformabrasil.saude.gov.br), CAAE 30836614.7.0000.0068. Study registered at Clinical Trials (clinicaltrials.gov), Identifier NCT03702153.

Comparison of Surgisis, Vypro II and TiMesh in contaminated and clean field.

PURPOSE: The study aimed to evaluate the histologic properties and infection resistance of three different mesh materials in a rat model. METHODS: Each mesh, in both infectious (n = 96) and non-infectious groups (n = 270), was positioned both in sublay (preperitoneally) and onlay (subcutaneously) locations. Properties of the biological (Surgisis; Cook Surgical), composite, partially resorbing (Vypro II mesh; Ethicon) and non-resorbing (TiMesh; GFE Medizintechnik GmbH) mesh were evaluated and compared. Animals were killed at 7, 21 and 90 days after implantation. The following parameters were evaluated to assess the host response to the mesh material: inflammation, vascularization, fibrosis, collagen formation, Ki67, and a foreign body reaction by granuloma formation (FBG). RESULTS: Surgisis mesh produced more pronounced inflammation and cell proliferation, and less intense granuloma formation, as well as fibrosis, compared to the other two groups. When the infected materials were examined, we found signs of local infection to be more often present in Surgisis group of animals. CONCLUSIONS: In the presence of bacterial contamination, no benefits were observed in the use of the Surgisis prosthesis over the use of TiMesh and Vypro II.

Comparative study of peritoneal adhesions after intraperitoneal implantation in rats of meshes of polypropylene versus polypropylene/polyglecaprone versus polyester/porcine collagen.

PURPOSE: To Compare the extent and intensity of adhesions formed between the intra-abdominal organs and the intraperitoneal implants of polypropylene mesh versus polypropylene/polyglecaprone versus polyester/porcine collagen used for correction of abdominal wall defect in rats. METHODS: After the defect in the abdominal wall, thirty Wistar rats were placed in three groups (ten animals each) for intraperitoneal mesh implant: polypropylene group, polypropylene/polyglecaprone group, and polyester/porcine collagen group. The macroscopic evaluation of the extent and intensity of adhesions was performed 21 days after the implant. RESULTS: The polypropylene group had a higher statistically significant impairment due to visceral adhesions (p value = 0.002) and a higher degree of intense adherence in relation to polypropylene/polyglecaprone and polyester/porcine collagen groups (p value<0.001). The polyester/porcine collagen group showed more intense adhesions than the polypropylene/polyglecaprone group (p value=0.035). CONCLUSIONS: The intraperitoneal implantation of polypropylene meshes to correct defects of the abdominal wall caused the appearance of extensive and firm adhesions to intra-abdominal structures. The use of polypropylene/polyglecaprone or polyester/porcine collagen tissue-separating meshes reduces the number and degree of adhesions formed.

The challenge of stress incontinence and pelvic organ prolapse: revisiting biologic mesh materials.

PURPOSE OF REVIEW: The present article reviews the history of mesh-related complications and regulations in SUI and POP repair settings, clinical outcomes associated with the use of biologic and synthetic mesh materials, and novel approaches using modified mesh materials. RECENT FINDINGS: Treatment of pelvic floor disorders, such as stress urinary incontinence (SUI) and pelvic organ prolapse (POP) commonly involves implantation of synthetic surgical mesh materials like polypropylene. Many synthetic mesh materials, however, are associated with a foreign body response upon implantation, which is characterized by fibrotic encapsulation. Complications, including erosion, infections, bleeding, and chronic pain, have led to warnings by regulatory agencies and the recall of several mesh products. To mitigate such complications, biologic mesh materials have been proposed as alternatives for SUI and POP repair. SUMMARY: Clinical outcomes of surgical repair of POP/SUI are similar between biologic and synthetic meshes, but biologic meshes have a lower incidence of adverse effects. Several strategies for modifying or functionalizing biological and synthetic meshes have shown promising results in preclinical studies.

Pure tissue repairs: a timely and critical revival.

"The majority of hernias can be satisfactorily repaired by using the tissues at hand. The use of mesh prosthesis should be restricted to those few hernias in which tension or lack of good fascial structures prevents a secure primary repair. This group includes large direct inguinal hernias and incisional hernias in which the defect is too large to close primarily without undue tension. Most recurrent hernias, because of this factor are best repaired with mesh prosthesis". These words, penned in 1960 by Francis Usher have reconfirmed what had been a mantra of the Shouldice Hospital (Usher in 81:847-854, 1960). The Shouldice Hospital has specialized in the treatment of abdominal wall hernias since 1945. It has, since its beginning, insisted on the fact that a thorough knowledge of anatomy coupled with large volumes of surgical cases would lead to unparalleled expertise. It was Cicero who taught us that "Practice, not intelligence or dexterity, will win the day"! Since the seminal contribution of Bassini (1844-1924), there have been no less than 80 procedures imitating his inguinal herniorrhaphy and much more since the introduction of mesh and mesh devices (Iason in Hernia. The Blakiston Company, Philadelphia, pp 475-604, 1940). All have failed to some extent and it appears that the common denominator for these failures was the inability to understand the importance of entering the preperitoneal space. Only Shouldice and McVay (Lotheissen, Narath) realized the shortcoming and have continued to thrive as a successful procedure. Entering the preperitoneal space eliminates any temptation to plicate the posterior inguinal wall, a layer normally deficient in direct inguinal hernias, but it also allows the identification of muscle layers rectus, transversus and internal oblique muscles which will go to reconstruct the posterior inguinal wall, without tension as reported by Schumpelick (Junge in 7(1):17-20, 2003).

Designing new synthetic materials for use in the pelvic floor: what is the problem with the existing polypropylene materials?

PURPOSE OF REVIEW: This review identifies the clinical complications associated with the design of the current polyproplylene mesh materials used for the treatment of stress urinary incontinence and pelvic organ prolapse. Following on from this, new alternative materials under development for pelvic floor repair are reviewed. RECENT FINDINGS: It is well accepted that the textile properties of the current polypropylene surgical meshes are not suitable for the pelvic floor environment. This together with the chemical nature of the current mesh leads to complications whenever implanted in the pelvic floor of women. New alternative materials for the repair of the pelvic floor have been developed with properties designed to be more appropriate for the biomechanical requirements and implantation requirements for the pelvic floor to reduce these clinical complications. To support this, these newer materials are being rigorously tested using more appropriate in-vitro regimes and animal models. SUMMARY: This chapter summarizes developments in the design of new materials for pelvic floor repair. These are being subjected to preclinical testing to exclude materials, which might fail to work in this dynamic environment by either showing a poor mechanical match to the requirements of the tissue or by provoking sustained inflammation. The hope is that new materials will prove effective without causing the high incidence of unacceptable side-effects currently seen with polypropylene mesh implants.

The use of implanted materials for treating women with pelvic organ prolapse and stress urinary incontinence.

PURPOSE OF REVIEW: To review the current clinical management of stress urinary incontinence and pelvic organ prolapse following the adverse complications seen in the use of polypropylene mesh to treat both. RECENT FINDINGS: Materials developed for use in abdominal hernia repair have not proven risk-free when used to support pelvic organs particularly when inserted via the vagina. Following unacceptably high levels of severe complications when high-density polypropylene mesh is inserted via the vagina to treat pelvic organ prolapse, reported over the last decade, there is now an agreed consensus between surgeons about surgical approaches and materials, which should be recommended for use in stress urinary incontinence and pelvic organ prolapse. SUMMARY: There is a need for new biomaterials and tissue engineered/regenerative medicine approaches to treat stress urinary incontinence and pelvic organ prolapse. New materials need to be evaluated critically in both preclinical and clinical studies before being adopted into routine clinical use.

Development of Valsartan Floating Matrix Tablets Using Low Density Polypropylene Foam Powder: In vitro and In vivo Evaluation.

The main purpose of the study was to develop valsartan floating tablets (VFT) via non-effervescent technique using low density polypropylene foam powder, carbopol, and xanthan gum by direct compression. Before compression, the particulate powdered mixture was evaluated for pre-compression parameters. The prepared valsartan tablets were evaluated for post-compression parameters, swelling index, floating lag time, in vitro buoyancy studies, and in vitro and in vivo X-ray imaging studies in albino rabbits. The result of all formulations for pre- and post-compression parameters were within the limits of USP. FTIR and DSC studies revealed no interaction between the drug and polymers used. The prepared floating tablets had good swelling and floating capabilities for more than 12 h with zero floating lag time. The release of valsartan from optimized formulation NF-2 showed sustained release up to 12 h; which was found to be non-Fickian release. Moreover, the X-ray imaging of optimized formulation (NF-2) revealed that tablet was constantly floating in the stomach region of the rabbit, thereby indicating improved gastric retention time for more than 12 h. Consequently, all the findings and outcomes have showed that developed valsartan matrix tablets could be effectively used for floating drug delivery system.

Risk factors of postoperative complications after emergency repair of incarcerated groin hernia for adult patients: a retrospective cohort study.

PURPOSE: This study aimed to explore risk factors of postoperative complications for adult patients with incarcerated groin hernia (IGH). METHODS: From January 2010 to December 2017, consecutive patients undergoing emergency hernia repair for IGH in our center were retrospectively reviewed. Postoperative complications, such as surgical site infection, seroma, hernia recurrence and mortality, were investigated, with risk factors for such complications analyzed using univariate and multivariate regressions. RESULTS: Sixty-four patients were included, with 51 males and 13 females (mean age 65.1, range 25-98 years). Ten patients (15.6%) underwent resection of necrotic bowel and anastomosis. 43 patients (67.2%) received open tension-free herniorrhaphy with polypropylene mesh, whereas the rest (32.8%) received herniorrhaphy without mesh. The overall postoperative complication rate was 40.6% (26/64), with an incisional complication rate of 31.2% (20/64) and an infection rate of 6.2% (4/64). At a median follow-up of 32 months, hernia recurrence and mortality were recorded in five cases each (7.8%). Mesh repair was associated with decreased recurrence rate compared with non-mesh repair (2.3% vs. 19.0%, p = 0.019). Diabetes mellitus (OR 8.611, 95%CI 1.292-57.405; p = 0.026) was an independent risk factor of postoperative complications, together with chronic obstructive pulmonary disease (COPD; OR 14.365, 95%CI 1.652-127.767, p = 0.016), intestinal necrosis (OR 14.260, 95%CI 1.079-188.460, p = 0.044), and general anesthesia (OR 14.543, 95%CI 1.682-125.711, p = 0.015) as risk for incisional complications after surgery. CONCLUSIONS: Diabetes mellitus was an independent risk factor of postoperative complications for IGH, along with COPD, intestinal necrosis and general anesthesia associated with incisional complications. The use of polypropylene mesh did not increase infection or recurrence rate in this cohort.

Comparative study of peritoneal adhesions after intraperitoneal implantation in rats of meshes of polypropylene versus polypropylene/polyglecaprone versus polyester/porcine collagen

Abstract Purpose To Compare the extent and intensity of adhesions formed between the intra-abdominal organs and the intraperitoneal implants of polypropylene mesh versus polypropylene/polyglecaprone versus polyester/porcine collagen used for correction of abdominal wall defect in rats. Methods After the defect in the abdominal wall, thirty Wistar rats were placed in three groups (ten animals each) for intraperitoneal mesh implant: polypropylene group, polypropylene/polyglecaprone group, and polyester/porcine collagen group. The macroscopic evaluation of the extent and intensity of adhesions was performed 21 days after the implant. Results The polypropylene group had a higher statistically significant impairment due to visceral adhesions (p value = 0.002) and a higher degree of intense adherence in relation to polypropylene/polyglecaprone and polyester/porcine collagen groups (p value<0.001). The polyester/porcine collagen group showed more intense adhesions than the polypropylene/polyglecaprone group (p value=0.035). Conclusions The intraperitoneal implantation of polypropylene meshes to correct defects of the abdominal wall caused the appearance of extensive and firm adhesions to intra-abdominal structures. The use of polypropylene/polyglecaprone or polyester/porcine collagen tissue-separating meshes reduces the number and degree of adhesions formed.

Comparative study of fibrosis induced by Marlex®, Parietex Composite®, Vicryl® and Ultrapro® meshes1.

PURPOSE: To evaluate the fibrosis induced by four different meshes: Marlex®, Parietex Composite®, Vicryl® and Ultrapro®. METHODS: Histological cutouts of abdominal wall were analyzed with polarized light 28 days after the meshes implants and colorized by picrosirius to identify the intensity of collagen types I and III, and their maturation index. RESULTS: When the four groups were compared, the total collagen area analyzed was bigger in groups A and D, with no difference between them. The collagen type I density was bigger in group A, with an average of 9.62 ± 1.0, and smaller in group C, with an average of 3.86 ± 0.59. The collagen type III density was similar in groups A, B and C, and bigger in group D. The collagen maturation index was different in each of the four groups, bigger in group A with 0.87, group B with 0.66, group D with 0.57 and group C with 0.33 (p = 0.0000). CONCLUSION: The most prominent fibrosis promotion in the given meshes was found on Marlex® (polypropylene mesh) and the Parietex Composite® (non-biodegradable polyester); the collagen maturation index was higher in the Marlex® mesh, followed by Ultrapro®, Parietex Composite® and Vicryl® meshes.

Synthesis, characterization and evaluation of transfection efficiency of dexamethasone conjugated poly(propyleneimine) nanocarriers for gene delivery#.

CONTEXT: Polypropylenimine (PPI), a cationic dendrimer with defined structure and positive surface charge, is a potent non-viral vector. Dexamethasone (Dexa) conveys to the nucleus through interaction with its intracellular receptor. OBJECTIVE: This study develops efficient and non-toxic gene carriers through conjugation of Dexa at various percentages (5, 10 and 20%) to the fourth and the fifth generation PPIs (PPIG4s and PPIG5s). MATERIALS AND METHODS: The 21-OH group of Dexa (0.536 mmol) was modified with methanesulfonyl chloride (0.644 mmol) to activate it (Dexa-mesylate), and then it was conjugated to PPIs using Traut's reagent. After dialysis (48 h) and lyophilization, the physicochemical characteristics of products (PPI-Dexa) including zeta potential, size, buffering capacity and DNA condensing capability were investigated and compared with unmodified PPIs. Moreover, the cytotoxicity and transfection activity of the Dexa-modified PPIs were assessed using Neuro2A cells. RESULTS: Transfection of PPIG4 was close to PEI 25 kDa. Although the addition of Dexa to PPIG4s did not improve their transfection, their cytotoxicity was improved; especially in the carrier to DNA weight ratios (C/P) of one and two. The Dexa conjugation to PPIG5s enhanced their transfection at C/P ratio of one in both 5% (1.3-fold) and 10% (1.6-fold) Dexa grafting, of which the best result was observed in PPIG5-Dexa 10% at C/P ratio of one. DISCUSSION AND CONCLUSIONS: The modification of PPIs with Dexa is a promising approach to improve their cytotoxicity and transfection. The higher optimization of physicochemical characteristics, the better cell transfection and toxicity will be achieved.

Comparative study of fibrosis induced by Marlex®, Parietex Composite®, Vicryl® and Ultrapro® meshes1

Abstract Purpose: To evaluate the fibrosis induced by four different meshes: Marlex®, Parietex Composite®, Vicryl® and Ultrapro®. Methods: Histological cutouts of abdominal wall were analyzed with polarized light 28 days after the meshes implants and colorized by picrosirius to identify the intensity of collagen types I and III, and their maturation index. Results: When the four groups were compared, the total collagen area analyzed was bigger in groups A and D, with no difference between them. The collagen type I density was bigger in group A, with an average of 9.62 ± 1.0, and smaller in group C, with an average of 3.86 ± 0.59. The collagen type III density was similar in groups A, B and C, and bigger in group D. The collagen maturation index was different in each of the four groups, bigger in group A with 0.87, group B with 0.66, group D with 0.57 and group C with 0.33 (p = 0.0000). Conclusion: The most prominent fibrosis promotion in the given meshes was found on Marlex® (polypropylene mesh) and the Parietex Composite® (non-biodegradable polyester); the collagen maturation index was higher in the Marlex® mesh, followed by Ultrapro®, Parietex Composite® and Vicryl® meshes.

Use of polypropylene mesh in contaminated and dirty strangulated hernias: short-term results.

PURPOSE: Synthetic non-absorbable meshes are routinely used in hernia surgery for clean cases but are avoided in the case of clean-contaminated or contaminated hernia or dirty cases to minimize the risk of infection. The present study was conducted to evaluate the outcome of polypropylene mesh in the settings of bowel resection performed for strangulated hernias of the abdominal wall. METHODS: This prospective observational study was conducted in the Department of Surgery of a teaching hospital in central India between 1st March 2015 and 31st Aug 2017. Adult patients > 18 years age, with abdominal wall hernias, presenting with strangulation, and requiring resection and anastomosis for gangrenous bowel were included in the study. Outcomes noted were wound infection, morbidity and mortality, need for the removal of the mesh, and recurrence of the hernia. RESULTS: 30 (22 men and 8 women) patients with strangulated hernias underwent emergency surgery with resection of gangrenous bowel and anastomosis. The 30 cases included 21 inguinal, seven incisional, one femoral and one umbilical hernia. 12 of the 30 cases having gross contamination of the operative wound due to perforated gangrenous bowel were classified as 'dirty'; while the remaining 18 cases with non-perforated gangrenous herniating bowel were classified as 'contaminated'. Wound infection occurred in 8/30 patients (26.67%); but these healed with antibiotics and dressing. Mesh removal was not required in any patient during entire study period. Two recurrences (6.7%; one inguinal and one incisional hernia) were observed. There was no mortality. CONCLUSION: The use of polypropylene mesh for contaminated and dirty strangulated hernias is effective and safe, with acceptable morbidity and good short-term results.

Regression of prostate tumors after intravenous administration of lactoferrin-bearing polypropylenimine dendriplexes encoding TNF-α, TRAIL, and interleukin-12.

The possibility of using gene therapy for the treatment of prostate cancer is limited by the lack of intravenously administered delivery systems able to safely and selectively deliver therapeutic genes to tumors. Given that lactoferrin (Lf) receptors are overexpressed on prostate cancer cells, we hypothesized that the conjugation of Lf to generation 3-diaminobutyric polypropylenimine dendrimer would improve its transfection and therapeutic efficacy in prostate cancer cells. In this study, we demonstrated that the intravenous administration of Lf-bearing DAB dendriplexes encoding TNFα resulted in the complete suppression of 70% of PC-3 and 50% of DU145 tumors over one month. Treatment with DAB-Lf dendriplex encoding TRAIL led to tumor suppression of 40% of PC-3 tumors and 20% of DU145 tumors. The treatment was well tolerated by the animals. Lf-bearing generation 3-polypropylenimine dendrimer is therefore a highly promising delivery system for non-viral gene therapy of prostate cancer.

E-beam sterilizable thermoplastics elastomers for healthcare devices: Mechanical, morphology, and in vivo studies.

The effect of electron beam radiation on ethylene-propylene diene terpolymer/polypropylene blends is studied as an attempt to develop radiation sterilizable polypropylene/ethylene-propylene diene terpolymer blends suitable for medical devices. The polypropylene/ethylene-propylene diene terpolymer blends with mixing ratios of 80/20, 50/50, 20/80 were prepared in an internal mixer at 165°C and a rotor speed of 50 rpm/min followed by compression molding. The blends and the individual components were radiated using 3.0 MeV electron beam accelerator at doses ranging from 0 to 100 kGy in air and room temperature. All the samples were tested for tensile strength, elongation at break, hardness, impact strength, and morphological properties. After exposing to 25 and 100 kGy radiation doses, 50% PP blend was selected for in vivo studies. Results revealed that radiation-induced crosslinking is dominating in EPDM dominant blends, while radiation-induced degradation is prevailing in PP dominant blends. The 20% PP blend was found to be most compatible for 20-60 kGy radiation sterilization. The retention in impact strength with enhanced tensile strength of 20% PP blend at 20-60 kGy believed to be associated with increased compatibility between PP and EPDM along with the radiation-induced crosslinking. The scanning electron micrographs of the fracture surfaces of the PP/EPDM blends showed evidences consistent with the above contentation. The in vivo studies provide an instinct that the radiated blends are safe to be used for healthcare devices.