Development of nitric oxide releasing visible light crosslinked gelatin methacrylate hydrogel for rapid closure of diabetic wounds.

Management of non-healing and slow to heal diabetic wounds is a major concern in healthcare across the world. Numerous techniques have been investigated to solve the issue of delayed wound healing, though, mostly unable to promote complete healing of diabetic wounds due to the lack of proper cell proliferation, poor cell-cell communication, and higher chances of wound infections. These challenges can be minimized by using hydrogel based wound healing patches loaded with bioactive agents. Gelatin methacrylate (GelMA) has been proven to be a highly cell friendly, cell adhesive, and inexpensive biopolymer for various tissue engineering and wound healing applications. In this study, S-Nitroso-N-acetylpenicillamine (SNAP), a nitric oxide (NO) donor, was incorporated in a highly porous GelMA hydrogel patch to improve cell proliferation, facilitate rapid cell migration, and enhance diabetic wound healing. We adopted a visible light crosslinking method to fabricate this highly porous biodegradable but relatively stable patch. Developed patches were characterized for morphology, NO release, cell proliferation and migration, and diabetic wound healing in a rat model. The obtained results indicate that SNAP loaded visible light crosslinked GelMA hydrogel patches can be highly effective in promoting diabetic wound healing.

Nonviral DNA Delivery System with Supramolecular PEGylation Formed by Host-Guest Pseudo-Block Copolymers.

A cationic supramolecular system based on host-guest pseudoblock copolymers was developed for nonviral DNA delivery. In this system, the macromolecular host was a cationic star-shaped polymer composed of a ß-cyclodextrin (ß-CD) core and multiple poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) chains grafted on the core, while the macromolecular guest was a linear adamantyl-ended poly(ethylene glycol) (mPEG-Ad). Pseudoblock copolymers were self-assembled from the polymeric host-guest pairs (typically, 1:1 molar ratio) in aqueous media through the inclusion of an adamantyl group at the end of guest polymer into the ß-CD cavity of host polymers. Through such an approach, the resultant supramolecular system was integrated with not only a superior DNA condensing ability due to the host polymer but also an outstanding polyplex-stabilizing ability as well as biocompatibility due to the guest polymer. The cationic star-shaped host polymers alone were capable of condensing plasmid DNA efficiently into nanoparticles (70-100 nm) with positive surface charge. They showed obviously lower cytotoxicity than PEI 25K (commercial branched polyethylenimine with a molecular weight around 25 kDa) in cell lines of L929, MB231, and Hela under high dose. In serum-free or serum-containing culture conditions, these host polymers exhibited either higher or lower in vitro DNA transfection efficiency as compared with PEI 25K in the three cell lines under study, which was dependent on the N/P ratios and PDMAEMA arm length. Upon incorporation of the PEG block through host-guest complexation with mPEG-Ad (i.e., supramolecular PEGylation), the resulting host-guest supramolecular systems exhibited even lower cytotoxicity than the host polymers alone. The polyplexes between plasmid DNA (pDNA) and the host-guest systems showed significantly improved stability in BSA-PBS buffer solution (pH 7.4) and enhanced in vitro DNA transfection efficiency in the cases of higher N/P ratios or longer PDMAEMA arms in all tested cell lines under both serum-free and serum-containing culture conditions, as compared with the corresponding polyplexes without supramolecular PEGylation. Further, through forming pseudoblock copolymer, the DNA transfection ability of the supramolecular system can be easily modulated and optimized either by changing the ratio between the guest and host or by using different hosts with varied PDMAEMA arm lengths.

Ameliorative effect of ozagrel, a thromboxane A2 synthase inhibitor, in hyperhomocysteinemia-induced experimental vascular cognitive impairment and dementia.

The present study investigates the effect of ozagrel, a selective thromboxane A2 (TXA2) inhibitor, in rat model of hyperhomocysteinemia (HHcy)-induced vascular cognitive impairment and dementia (VCID). Wistar rats were administered L-methionine (1.7 g/kg/day; p.o. × 8 weeks) to induce VCID. Morris water maze (MWM) test was employed to assess learning and memory. Endothelial dysfunction was assessed in the isolated aorta by observing endothelial-dependent vasorelaxation and levels of serum nitrite. Various biochemical and histopathological estimations were also performed. L-methionine produced significant impairment in endothelium-dependent vasorelaxation and decreases serum nitrite levels indicating endothelial dysfunction. Further, these animals performed poorly on MWM, depicting impairment of learning and memory. Further, a significant rise in brain oxidative stress level (indicated by increase in brain thiobarbituric acid-reactive species and decrease in reduced glutathione levels), brain acetylcholinesterase activity, brain myeloperoxidase activity, brain TNF-α and IL-6 levels, and brain leukocyte (neutrophil) infiltration was also observed. Treatment of ozagrel (10 and 20 mg/kg, p. o.)/donepezil (0.5 mg/kg, i.p., serving as standard) ameliorated L-methionine-induced endothelial dysfunction, memory deficits, and biochemical and histopathological changes. It may be concluded that ozagrel markedly improved endothelial dysfunction, learning and memory, and biochemical and histopathological alteration associated with L-methionine-induced VCID and that TXA2 can be considered as an important therapeutic target for the management of VCID.

Gelatin Methacryloyl Bioadhesive Improves Survival and Reduces Scar Burden in a Mouse Model of Myocardial Infarction.

Background Delivery of hydrogels to the heart is a promising strategy for mitigating the detrimental impact of myocardial infarction (MI). Challenges associated with the in vivo delivery of currently available hydrogels have limited clinical translation of this technology. Gelatin methacryloyl (GelMA) bioadhesive hydrogel could address many of the limitations of available hydrogels. The goal of this proof-of-concept study was to evaluate the cardioprotective potential of GelMA in a mouse model of MI. Methods and Results The physical properties of GelMA bioadhesive hydrogel were optimized in vitro. Impact of GelMA bioadhesive hydrogel on post-MI recovery was then assessed in vivo. In 20 mice, GelMA bioadhesive hydrogel was applied to the epicardial surface of the heart at the time of experimental MI. An additional 20 mice underwent MI but received no GelMA bioadhesive hydrogel. Survival rates were compared for GelMA-treated and untreated mice. Left ventricular function was assessed 3 weeks after experimental MI with transthoracic echocardiography. Left ventricular scar burden was measured with postmortem morphometric analysis. Survival rates at 3 weeks post-MI were 89% for GelMA-treated mice and 50% for untreated mice (P=0.011). Left ventricular contractile function was better in GelMA-treated than untreated mice (fractional shortening 37% versus 26%, P<0.001). Average scar burden in GelMA-treated mice was lower than in untreated mice (6% versus 22%, P=0.017). Conclusions Epicardial GelMA bioadhesive application at the time of experimental MI was performed safely and was associated with significantly improved post-MI survival compared with control animals. In addition, GelMA treatment was associated with significantly better preservation of left ventricular function and reduced scar burden.

In vitro inhalation cytotoxicity testing of therapeutic nanosystems for pulmonary infection.

Due to the increasing need of new treatment options against bacterial lung infections, novel antimicrobial peptides (AMPs) are under development. Local bioavailability and less systemic exposure lead to the inhalation route of administration. Combining AMPs with nanocarriers (NCs) into nanosystems (NSs) might be a technique for improved results. An air-liquid interface (ALI) in vitro inhalation model was set up including a human alveolar lung cell line (A549) and an optimized exposure system (P.R.I.T.® ExpoCube®) to predict acute local lung toxicity. The approach including aerosol controls (cupper-II-sulfate and lactose) delivered lowest observable adverse effect levels (LOAELs). Different combinations of AMPs (AA139, M33) and NCs (polymeric nanoparticles (PNPs), micelles and liposomes) were tested under ALI and submerged in vitro conditions. Depending on the nature of AMP and NCs, packing of AMPs into NSs reduced the AMP-related toxicity. Large differences were found between the LOAELs determined by submerged or ALI testing with the ALI approach indicating higher sensitivity of the ALI model. Since aerosol droplet exposure is in vivo relevant, it is assumed that ALI based results represents the more significant source than submerged testing for in vivo prediction of local acute lung toxicity. In accordance with the current state-of-the-art view, this study shows that ALI in vitro inhalation models are promising tools to further develop in vitro methods in the field of inhalation toxicology.

Injectable and degradable methacrylic acid hydrogel alters macrophage response in skeletal muscle.

After severe trauma, skeletal muscle cannot repair itself leading to scar tissue formation and functional impairment. A novel approach to overcome this issue is to alter the fibrotic response in muscle using regenerative biomaterials, such as those containing methacrylic acid (MAA). In the skin, MAA-based materials have been shown to promote wound healing and new vessel formation, through endogenous mechanisms, including macrophage polarization; however, MAA has yet to be studied outside the skin. To study the innate immune response to MAA in skeletal muscle, MAA-poly(ethylene glycol) (MAA-PEG) hydrogels were synthesized with degradation rates of either 2 (fast-degrading) or 7 days (slow-degrading). When injected into the tibialis anterior muscle of mice, both slow- and fast-degrading MAA hydrogels increased the expression of Il-10, Tnfα and M2 macrophage markers (Fizz1 and Arg for slow-and fast-degrading, respectively). Moreover, the slow degrading MAA hydrogel decreased the number of pro-inflammatory MHCII+ macrophages. An unbiased t-distributed stochastic neighbor embedding (tSNE) analysis suggested the involvement of other immune cells beyond just macrophages in the effect of MAA on skeletal muscle. Overall, this study shows that MAA hydrogels bias macrophages towards a pro-regenerative phenotype.

Pectin-based (LA-co-MAA) semi-IPNS as a potential biomaterial for colonic delivery of oxaliplatin.

This study describes the fabrication of chemically crosslinked pectin-based LA-co-MAA hydrogels through free radical polymerization technique for the colonic delivery of oxaliplatin. Methylene bisacrylamide was used as a crosslinking agent and ammonium persulfate as an initiator. The successful fabrication and drug loading were confirmed through Fourier transform infrared spectroscopy (FTIR). The thermal investigations through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) suggested the higher thermal stability of the unloaded and OXP-loaded formulations as compared to the raw materials. X-ray diffraction (XRD) analysis showed a decrease in crystallinity after crosslinking. The swelling, drug loading, and drug release were increased with an increase in the concentration of pectin and lactic acid (LA) while methacrylic acid (MAA) displayed an inverse behavior. The in-vitro biodegradability was evaluated against lysozyme and collagenase. The results showed that the hydrogels were stable against blank PBS as compared to lysozyme and collagenase. MTT-assay proved that the blank hydrogels were cytocompatible while free OXP and OXP-loaded hydrogels displayed dose-dependent effect against Vero, MCF-7, and HCT-116 cell lines. The oral tolerability study in rabbits confirmed that the hydrogel dispersion was well-tolerable up to 3650 mg/kg of body weight without causing any histopathological or hematological changes when compared with the control group.

Reocclusion of the treated vessel due to endothelial injury after mechanical thrombectomy in a patient with acute ischaemic stroke.

A 92-year-old woman developed sudden consciousness disturbance, global aphasia and right hemiparesis. She had atrial fibrillation and cardioembolic stroke was diagnosed. Tissue plasminogen activator was administered, and endovascular treatment was initiated. The left middle cerebral artery was occluded and complete recanalisation was achieved after direct aspiration first-pass technique. However, MRI immediately after treatment showed reocclusion. Endovascular treatment was repeated and complete recanalisation was achieved. There was no evidence of cerebral artery dissection, but angiography soon after the second procedure revealed early reocclusion. Ozagrel, an antiplatelet agent, was administered intravenously and prevented reocclusion. Endothelial injury was speculated to have occurred during the first mechanical thrombectomy, leading to recurrent occlusion. Though the patient continued to have right hemiparesis, she recovered from her consciousness disturbance and aphasia after re-treatment.

The crucial role of macromolecular engineering, drug encapsulation and dilution on the thermoresponsiveness of UCST diblock copolymer nanoparticles used for hyperthermia.

Poly(acrylamide-co-acrylonitrile) (P(AAm-co-AN)), an upper critical solution temperature (UCST)-type copolymer in water, was synthesized by reversible addition fragmentation chain transfer (RAFT) copolymerization and used as a macro-RAFT agent for the polymerization of oligo(ethylene glycol) methyl ether methacrylate (OEGMA) to yield amphiphilic diblock P(AAm-co-AN)-b-POEGMA copolymer. A series of copolymers with different AN content was obtained allowing to finely tune the UCST behavior (cloud point (Tt-UCST) from 35 to 78 °C). Addition of the POEGMA block did not modify the Tt-UCST regardless its Mn but provided a lower critical solution temperature behavior at high temperature. Nanoparticles were then formulated by the nanoprecipitation technique revealing that copolymers with higher Tt-UCST yield smaller, better-defined nanoparticles. Eventually, doxorubicin (Dox) was encapsulated into nanoparticles made from the copolymer having a Tt-UCST close to mild hyperthermia (~43 °C). Surprisingly, Dox encapsulation increased Tt-UCST and gave smaller nanoparticles as opposed to their unloaded counterparts. The dilution of the suspension also led to a decrease of Tt-UCST. No obvious hyperthermia effect was observed on the cytotoxicity of Dox-loaded nanoparticles. Our study highlighted the influence of macromolecular engineering, drug encapsulation and nanoparticle dilution on UCST behavior, important features often overlooked despite their crucial impact in the development of thermosensitive nanoscale drug delivery systems.

Transscleral sustained ranibizumab delivery using an episcleral implantable device: Suppression of laser-induced choroidal neovascularization in rats.

Successful treatment of age-related macular diseases requires an effective controlled drug release system with less invasive route of administration in the eye to reduce the burden of frequent intravitreal injections for patients. In this study, we developed an episcleral implantable device for sustained release of ranibizumab, and evaluated its efficacy on suppression of laser-induced choroidal neovascularization (CNV) in rats. We tested both biodegradable and non-biodegradable sheet-type devices consisting of crosslinked gelatin/chitosan (Gel/CS) and photopolymerized poly(ethyleneglycol) dimethacrylate that incorporated collagen microparticles (PEGDM/COL). In vitro release studies of FITC-labeled albumin showed a constant release from PEGDM/COL sheets compared to Gel/CS sheets. The Gel/CS sheets gradually biodegraded in the sclera during the 24-week implantation; however, the PEGDM/COL sheets did not degrade. FITC-albumin was detected in the retina during 18 weeks implantation in the PEGDM/COL sheet-treated group, and was detected in the Gel/CS sheet-treated group during 6 weeks implantation. CNV was suppressed 18 weeks after application of ranibizumab-loaded PEGDM/COL sheets compared to a placebo PEGDM/COL sheet-treated group, and to the intravitreal ranibizumab-injected group. In conclusion, the PEGDM/COL sheet device suppressed CNV via a transscleral administration route for 18 weeks, indicating that prolonged sustained ranibizumab release could reduce the burden of repeated intravitreal injections.

Nano spray dryer for vectorizing α-galactosylceramide in polymeric nanoparticles: A single step process to enhance invariant Natural Killer T lymphocyte responses.

The recognition of α-galactosylceramide (αGC), a high-affinity CD1d antigen, by the invariant Natural Killer T (iNKT) lymphocytes results in potent immunostimulatory responses that have been exploited in advanced cancer patients. Therefore, to improve αGC biological activity, several studies vectorized this agonist in PLGA and/or PEG-based nanoparticles. Despite promising findings, these approaches require several steps, from organic solvent decontamination through extrusion in membrane systems. Using a nano spray dryer, we vectorized αGC into a cationic copolymer (dimethylaminoethyl methacrylate, butyl methacrylate and methyl methacrylate - DBM) in a single step process, free of organic solvent. This methodology allowed the production of stable αGC-vectorized nanoparticles (DBM + αGC) with a more potent biological activity than the free agonist. DBM nanoparticles improved in vivo αGC loading into the CD1d molecule and induced a higher frequency of IFN-γ-expressing iNKT cells. Consequently, mice treated with DBM + αGC presented higher levels of serum IFN-γ than those treated with free agonist. Also, vectorized nanoparticles improved αGC ability to control the growth of murine lung metastatic carcinoma. Thus, this is the first study showing that nano spray dryer technology is a simple and alternative approach to enhance iNKT responses.

Cytoplasmic delivery of functional siRNA using pH-Responsive nanoscale hydrogels.

The progress of short interfering RNA (siRNA) technologies has unlocked the development of novel alternatives for the treatment of a myriad of diseases, including viral infections, autoimmune disorders, or cancer. Nevertheless, the clinical use of these therapies faces significant challenges, mainly overcoming the charged and large nature of these molecules to effectively enter the cell. In this work, we developed a cationic polymer nanoparticle system that is able to load siRNA due to electrostatic interactions. The pH-responsiveness and membrane-disrupting ability of these carriers make them suitable intracellular delivery vehicles. In the work presented herein we synthesized, characterized, and evaluated the properties of nanoparticles based on 2-diethylaminoethyl methacrylate and tert-butyl methacrylate copolymers. A disulfide crosslinker was incorporated in the nanogels to enable the degradation of the nanoparticles in reductive environments, showing no significant changes on their physicochemical properties. The capability of the developed nanogels to be internalized, deliver siRNA, and induce gene knockdown were demonstrated using a human epithelial colorectal adenocarcinoma cell line. Overall, these findings suggest that this platform exhibits desirable characteristics as a potential siRNA-delivery platform.

pH-responsive CAP-co-poly(methacrylic acid)-based hydrogel as an efficient platform for controlled gastrointestinal delivery: fabrication, characterization, in vitro and in vivo toxicity evaluation.

Cellulose acetate phthalate-based pH-responsive hydrogel was synthesized for fabrication of polymeric matrix tablets for gastro-protective delivery of loxoprofen sodium. Cellulose acetate phthalate (CAP) was cross-linked with methacrylic acid (MAA) using free radical polymerization technique. Fourier transform infrared (FTIR) spectra confirmed the formation of cross-linked structure of CAP-co-poly(methacrylic acid). Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) confirmed the thermal stability of polymeric networks, and scanning electron microscopy (SEM) and energy-dispersive X-ray spectrum (EDS) images unveiled that the prepared formulations were porous in nature and thus the developed formulations had shown better diffusibility. Swelling and in vitro drug release was performed at various pHs and maximum swelling and release was obtained at pH 7.4, while swelling and release rate was very low at pH 1.2 which confirmed the pH-responsive behavior of CAP-co-poly(MAA). CAP-co-poly(MAA) copolymer prevents the release of loxoprofen sodium into the stomach due to reduced swelling at gastric pH while showing significant swelling and drug release in the colon. Cytotoxicity studies revealed higher biocompatibility of fabricated hydrogel. Acute oral toxicity studies were performed for the evaluation and preliminary screening of safety profile of the developed hydrogels. Matrix tablets were evaluated for release behavior at simulated body pH. The investigations performed for analysis of hydrogels and fabricated matrix tablets indicated the controlled drug release and gastro-protective drug delivery of CAP-co-poly(MAA) hydrogels and pH-sensitive matrix tablets for targeted delivery of gastro-sensitive/irritative agents. Graphical abstract.

HPMA-PLGA Based Nanoparticles for Effective In Vitro Delivery of Rifampicin.

PURPOSE: Tuberculosis (TB) chemotherapy witnesses some major challenges such as poor water-solubility and bioavailability of drugs that frequently delay the treatment. In the present study, an attempt to enhance the aqueous solubility of rifampicin (RMP) was made via co-polymeric nanoparticles approach. HPMA (N-2-hydroxypropylmethacrylamide)-PLGA based polymeric nanoparticulate system were prepared and evaluated against Mycobacterium tuberculosis (MTB) for sustained release and bioavailability of RMP to achieve better delivery. METHODOLOGY: HPMA-PLGA nanoparticles (HP-NPs) were prepared by modified nanoprecipitation technique, RMP was loaded in the prepared NPs. Characterization for particle size, zeta potential, and drug-loading capacity was performed. Release was studied using membrane dialysis method. RESULTS: The average particles size, zeta potential, polydispersity index of RMP loaded HPMA-PLGA-NPs (HPR-NPs) were 260.3 ± 2.21 nm, -6.63 ± 1.28 mV, and 0.303 ± 0.22, respectively. TEM images showed spherical shaped NPs with uniform distribution without any cluster formation. Entrapment efficiency and drug loading efficiency of HPR-NPs were found to be 76.25 ± 1.28%, and 26.19 ± 2.24%, respectively. Kinetic models of drug release including Higuchi and Korsmeyer-peppas demonstrated sustained release pattern. Interaction studies with human RBCs confirmed that RMP loaded HP-NPs are less toxic in this model than pure RMP with (p < 0.05). CONCLUSIONS: The pathogen inhibition studies revealed that developed HPR-NPs were approximately four times more effective with (p < 0.05) than pure drug against sensitive Mycobacterium tuberculosis (MTB) stain. It may be concluded that HPR-NPs holds promising potential for increasing solubility and bioavailability of RMP.

Drug carriers with star polymer structures.

In this review we summarize several synthetic approaches to the advanced synthesis of star-like polymer-based drug carriers. Moreover, their application as nanomedicines for therapy or the diagnosis of neoplastic diseases and their biodistribution are reviewed in detail. From a broad spectrum of star-like systems, we focus only on fully water-soluble systems, mainly based on poly(ethylene glycol) or N-(2-hydroxypropyl)methacrylamide polymer and copolymer arms and polyamidoamine dendrimers serving as the core of the star-like systems.

Controlled drug delivery from 3D printed two-photon polymerized poly(ethylene glycol) dimethacrylate devices.

Controlled drug delivery systems have been utilized to enhance the therapeutic effects of many drugs by delivering drugs in a time-dependent and sustained manner. Here, with the aid of 3D printing technology, drug delivery devices were fabricated and tested using a model drug (fluorophore: rhodamine B). Poly(ethylene glycol) dimethacrylate (PEGDMA) devices were fabricated using a two-photon polymerization (TPP) system and rhodamine B was homogenously entrapped inside the polymer matrix during photopolymerization. These devices were printed with varying porosity and morphology using varying printing parameters such as slicing and hatching distance. The effects of these variables on drug release kinetics were determined by evaluating device fluorescence over the course of one week. These PEGDMA-based structures were then investigated for toxicity and biocompatibility in vitro, where MTS assays were performed using a range of cell types including induced pluripotent stem cells (iPSCs). Overall, tuning the hatching distance, slicing distance, and pore size of the fabricated devices modulated the rhodamine B release profile, in each case presumably due to resulting changes in the motility of the small molecule and its access to structure edges. In general, increased spacing provided higher drug release while smaller spacing resulted in some occlusion, preventing media infiltration and thus resulting in reduced fluorophore release. The devices had no cytotoxic effects on human embryonic kidney cells (HEK293), bone marrow stromal stem cells (BMSCs) or iPSCs. Thus, we have demonstrated the utility of two-photon polymerization to create biocompatible, complex miniature devices with fine details and tunable release of a model drug.

68Ga-PSMA PET/CT Replacing Bone Scan in the Initial Staging of Skeletal Metastasis in Prostate Cancer: A Fait Accompli?

PURPOSE: 68Ga ligands targeting prostate-specific membrane antigen (PSMA) are rapidly emerging as a significant step forward in the management of prostate cancer. PSMA is a type II transmembrane protein with high expression in prostate carcinoma cells. We prospectively evaluated the use of 68Ga-PSMA positron emission tomography/computed tomography (PET/CT) in patients with prostate cancer and compared the results to those for technetium-99m (99mTc)-10-metacyloyloxydecyl dihydrogen phosphate (MDP) bone scintigraphy (BS). PATIENTS AND METHODS: A total 113 patients with biopsy-proven prostate cancer referred for standard-of-care BS were prospectively enrolled onto this study. 68Ga-PSMA PET/CT was performed after BS. Metastasis diagnosed on each technique was compared against a final diagnosis based on CT, magnetic resonance imaging, skeletal survey, clinical follow-up, and histologic correlation. RESULTS: Ninety-one bone lesions were interpreted as bone metastases in 25 men undergoing 68Ga-PSMA PET/CT compared to only 61 lesions in 19 men undergoing 99mTc-MDP BS. Of the 7 bone scans that missed skeletal metastases, 54% of these missed lesions were due to either marrow or lytic skeletal metastases. The median standardized uptake value in all malignant bone lesions was 13.84. 68Ga-PSMA PET/CT showed significantly higher sensitivity and accuracy than BS (96.2% vs. 73.1%, and 99.1% vs. 84.1%) for the detection of skeletal lesions. For extraskeletal lesions, 68Ga-PSMA PET/CT showed an additional 96 unexpected lesions with a median standardized uptake value of 17.6. CONCLUSION: 68Ga-PSMA PET/CT is superior to and can potentially replace bone scan in the evaluation for skeletal metastases in the clinical and trial setting because of its ability to detect lytic and bone marrow metastases.

E-selectin-targeted copolymer reduces atherosclerotic lesions, adverse cardiac remodeling, and dysfunction.

Endothelial activation with up-regulation of E-selectin adhesion molecules mediates leukocyte rolling along the vascular wall and controls inflammation in many diseases including atherosclerosis and heart failure. Therefore, we aimed to test the hypothesis that inhibition of E-selectin-mediated interactions by a new E-selectin-targeted copolymer could inhibit the progression of atherosclerosis. To target E-selectin on activated endothelium, we developed a new N-(2-hydroxypropyl)methacrylamide (HPMA)-based E-selectin binding copolymer with or without dexamethasone (Dex) (designated P-(Esbp)-Dex and P-Esbp, respectively). To determine the effect of P-(Esbp)-Dex and P-Esbp on atherosclerosis, we allocated ApoE (-/-) mice on a high fat diet, to weekly intra-peritoneal injections of either 1) P-Esbp; 2) P-(Esbp)-Dex; 3) free Dex (1 mg/kg) or 4) saline, for four weeks. Aortic atherosclerosis and left ventricular (LV) remodeling and function were assessed by serial ultrasound studies and histology. Monocytes and macrophages were characterized by flow cytometry. After four weeks of treatment, P-Esbp effectively targeted aortic atherosclerotic lesions. Both P-Esbp and P-(Esbp)-Dex reduced wall thickening of the ascending aortas. However, only the drug-free copolymer (P-Esbp) significantly decreased the areas of necrotic core in the plaques and switched spleen macrophages toward an anti-inflammatory (M2) phenotype. Furthermore, P-Esbp attenuated adverse LV remodeling and dysfunction in ApoE (-/-) mice. In summary, P-Esbp copolymer targets activated endothelial cells, regresses and stabilizes atherosclerotic plaques, and prevents adverse LV remodeling and dysfunction in ApoE (-/-) mice. Our results suggest a new, drug-free macromolecular therapy to treat vascular inflammation.

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

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

Efficacy of a Eudragit L30D-55 encapsulated oral vaccine containing inactivated bacteria (Lactococcus garvieae/Streptococcus iniae) in rainbow trout (Oncorhynchus mykiss).

The efficacy of a Eudragit L30D-55 encapsulated vaccine against Lactococcus garvieae and Streptococcus iniae was investigated in rainbow trout. Fish were divided into four groups and fed the different experimental feeds. Groups were: A) fish immunized by Eudragit-coated pellets containing vaccine, B) fish immunized by vaccine-coated pellets without Eudragit, C) fish fed Eudragit-coated pellets without vaccine and D) fish fed pellets without vaccine orEudragit (control group). In groups A and B, the vaccination was conducted for 14 days. Similar to groups A and B, fish of group C were fed 14 days with pellets coated with Eudragit and afterwards they were fed control diet. Serum samples were taken on day 0, 20, 40 and 60 of the experiment. After 60 days, fish were challenged with L. garvieae and S. iniae. In almost all groups, innate immunity components including alternative complement activity, lysozyme activity, bactericidal activity, IgM and total protein showed no significant changes during the 60 days that the experiment lasted. However, the blood respiratory burst activity and lysozyme activity showed a significant increase on day 20 of experiment in groups B and D respectively (P < 0.05). The relative expression of immune-related genes including IL-6 and IgM genes was higher in vaccinated fish, with the highest expression in those immunized by Eudragit-coated pellets (Group A). In addition, the relative expression of IL-6 and IgM peaked on day 20 but decreased on day 60 in vaccinated groups. The ELISA antibody titer against L. garvieae increased from day 20 and peaked on day 60 of experiment (P < 0.05). Also, the antibody titer against L. garvieae was higher in fish immunized by Eudragit-coated pellets (Group A) compared to fish of group C and control. After bacterial challenge, a survival percentages of % 85 ±â€¯7.07% (challenged with S. iniae) and % 72.21 ±â€¯7.8% (challenged with L. garvieae) were observed respectively in groups immunized with pellets coated with Eudragit L30D-55 (Group A), which were higher than survival percentages obtained in other experimental groups (P < 0.05). The results of the present study demonstrate that the oral administration of Eudragit L30D-55-encapsulated vaccine appropriately protects rainbow trout against Lactococcus garvieae and Streptococcus iniae.