Endoscopic near-infrared photoimmunotherapy in an orthotopic head and neck cancer model.

Near-infrared photoimmunotherapy (NIR-PIT) is a cell selective cancer therapy that uses an antibody-photoabsorber (IRDye700DX, IR700) conjugate (APC) and NIR light. NIR-PIT targeting epidermal growth factor receptor (EGFR) in head and neck cancer (HNC) was conditionally approved in Japan in 2020. APC-bound tumors can be detected using endoscopic fluorescence imaging, whereas NIR light can be delivered using endoscopic fiber optics. The aims of this study were: (1) to assess the feasibility of endoscopic NIR-PIT in an orthotopic HNC model using a CD44-expressing MOC2-luc cell line; and (2) to evaluate quantitative fluorescence endoscopic imaging prior to and during NIR-PIT. The results were compared in 3 experimental groups: (1) untreated controls, (2) APC injection without light exposure (APC-IV), and (3) APC injection followed by NIR light exposure (NIR-PIT). APC injected groups showed significantly higher fluorescence signals for IR700 compared with the control group prior to therapeutic NIR light exposure, and the fluorescence signal significantly decreased in the NIR-PIT group after light exposure. After treatment, the NIR-PIT group showed significantly attenuated bioluminescence compared with the control and the APC-IV groups. Histology demonstrated diffuse necrotic death of the cancer cells in the NIR-PIT group alone. In conclusion, endoscopically delivered light combined with quantitative fluorescence imaging can be used to "see and treat" HNC. This method could also be applied to other types of cancer approachable with endoscopy.

Size-dependent biodistribution of thiol-organosilica nanoparticles and F4/80 protein expression in the genital tract of female mice after intravaginal administration.

Recently the vaginal route consider as an ideal route for drug delivery systems (DDS) administration. This is because, it is suitable for lower drug dosage, higher drug concentration in the genital tract tissues and lower drug concentration in pregnant women blood circulation. However, the vaginal route administration faces many challenges due to the physiology as well as the complexity of vaginal tissue histology. Here in this study, during diestrus stage (optimal condition for foreign substance internalization), single or dual size of fluorescent thiol-organosilica nanoparticles (tOS-NPs) were administrated intravaginally. The biodistribution and reactivity of tOS-NPs in different tissues of the female genital tract were investigated under the fluorescence microscope. Furthermore, using immunohistochemical staining, the expression of F4/80 protein and the role of macrophages in transport and re-location of tOS-NPs from vaginal lumen into different genital tissues or other organs were investigated. This study showed that, tOS-NPs size and type of tissue are important in biodistribution and uptake of tOS-NPs in the genital tract. Small size (100 nm) of tOS-NPs was highly accumulated in the genital tract tissues especially endometrial epithelium compared with large tOS-NPs (1000 nm). Contradictory, the large size induced the expression of F4/80 protein and the number of vaginal macrophages compared with small size. However, both small and large sizes of tOS-NPs were found co-localized with F4/80+ macrophages, located in the vaginal, endometrial and ovarian tissues. The tOS-NPs intravaginally administrated were found in the splenic tissues, indicating its ability to enter the blood circulation from the vaginal lumen. Additionally, the high accumulation of tOS-NPs in the endometrial epithelium indicated the endometrial first pass effect of tOS-NPs. As a result, high concentration of tOS-NPs in the endometrial epithelium may reduce the concentration of tOS-NPs-based DDS in the blood circulation and their side effects. Furthermore, during vaginal tissue optimal condition (diestrus stage), understanding the fate and biodistribution of tOS-NPs will introduce important data about the development of save and effective DDS for the pregnant women.

Diagnostic imaging in near-infrared photoimmunotherapy using a commercially available camera for indocyanine green.

Near-infrared photoimmunotherapy (NIR-PIT) is a new type of cancer treatment, which was recently approved in Japan for patients with inoperable head and neck cancer. NIR-PIT utilizes antibody-IRDye700DX (IR700) conjugates and NIR light at a wavelength of 690 nm. NIR light exposure leads to physicochemical changes in the antibody-IR700 conjugate cell receptor complex, inducing rapid necrotic cell death. Just as fluorescence guided surgery is useful for surgeons to resect tumors completely, real-time information of tumor locations would help clinicians irradiate NIR light more precisely. IR700 is a fluorescence dye that emits at 702 nm; however, there is no clinically available device optimized for detecting this fluorescence. On the other hand, many indocyanine green (ICG) fluorescence imaging devices have been approved for clinical use. Therefore, we investigated whether LIGHTVISION, one of the clinically available ICG cameras, could be employed for tumor detection. We hypothesized that irradiation with even low-power 690-nm laser light, attenuated by 99% with a neutral-density filter, could be detected with LIGHTVISION without fluorescence decay or therapeutic effect because of the long emission tail of IR700 beyond 800 nm (within the detection range of LIGHTVISION). We demonstrated that the LIGHTVISION camera, originally designed for ICG detection, can detect the tail of IR700 fluorescence in real time, thus enabling the visualization of target tumors.

Targeted Photodynamic Therapy (PDT) of Lung Cancer with Biotinylated Silicon (IV) Phthalocyanine.

BACKGROUND: Lung cancer is the leading cause of cancer-associated mortality in the world. Traditional cancer therapies prolong the life expectancy of patients but often suffer from adverse reactions. Photodynamic Therapy (PDT) has been recommended as a treatment option for lung cancer in several countries, due to its non-invasive procedures, high selectivity and weak side effects. OBJECTIVE: We have designed and synthesized a biotin receptor-targeted silicon phthalocyanine (IV) (compound 1) which showed a good therapeutic effect on biotin receptor-positive tumors. Since the overexpression of Biotin Receptor (BR) is also present in human lung cancer cells (A549), we explored the therapeutic properties of compound 1 on A549 xenograft tumor models. METHODS: The selectivity of compound 1 toward A549 cells was studied with a fluorescence microscope and IVIS Spectrum Imaging System. The cytotoxicity was measured using the MTT assay. In vivo anti-tumor activity was investigated on the nude mice bearing A549 xenografts. RESULTS: In vitro assays proved that compound 1 could selectively accumulate in A549 cells via the BR-mediated internalization. In vivo imaging and distribution experiments showed that compound 1 could selectively accumulate in tumor tissues of tumor-bearing mice. After 16 days of the treatment, the volumes of tumor in the PDT group were obviously smaller than that in other groups. CONCLUSION: This study demonstrates that compound 1 is a promising photosensitizer and has broad application prospects in clinical PDT of lung cancers.

Emergence of Nanotechnology to Fight HIV Sexual Transmission: The Trip of G2-S16 Polyanionic Carbosilane Dendrimer to Possible Pre-Clinical Trials.

Development of new, safe, and effective microbicides to prevent human immunodeficiency virus HIV sexual transmission is needed. Unfortunately, most microbicides proved ineffective to prevent the risk of HIV-infection in clinical trials. We are working with G2-S16 polyanionic carbosilane dendrimer (PCD) as a new possible vaginal topical microbicide, based on its short reaction times, wide availability, high reproducibility, and quantitative yields of reaction. G2-S16 PCD exerts anti-HIV activity at an early stage of viral replication, by blocking gp120/CD4/CCR5 interaction, and providing a barrier against infection for long periods of time. G2-S16 PCD was stable at different pH values, as well as in the presence of seminal fluids. It maintained the anti-HIV activity against R5/X4 HIV over time, did not generate any type of drug resistance, and retained the anti-HIV effect when exposed to semen-enhanced viral infection. Importantly, G2-S16 PCD did not modify vaginal microbiota neither in vitro or in vivo. Histopathological examination did not show vaginal irritation, inflammation, lesions, or damage in the vaginal mucosa, after administration of G2-S16 PCD at different concentrations and times in female mice and rabbit animal models. Based on these promising data, G2-S16 PCD could become a good, safe, and readily available candidate to use as a topical vaginal microbicide against HIV.

A super-stretchable, self-healing and injectable supramolecular hydrogel constructed by a host-guest crosslinker.

Supramolecular hydrogels based on host-guest interactions have drawn considerable attention due to their unique properties and promising applications. However, it is still a great challenge to construct supramolecular hydrogels that simultaneously achieve mechanical strength, processability, and biocompatibility. Herein, we present a rational design of a "supramolecular crosslinker" approach to fabricate a new host-guest hydrogel with super-stretchability, self-healing, and injectable properties and excellent biocompatibility. The star-shaped supramolecular crosslinker is formed by the host-guest interactions between octa-cyclodextrin polyhedral oligomeric silsesquioxane (OCDPOSS) and acrylamide-modified adamantane (Ad-AAm). Supramolecular hydrogels can be briefly prepared by UV-initiated copolymerization of acrylamide and supramolecular crosslinkers. Supramolecular hydrogels present impressive mechanical properties due to rigid POSS as the core of the supramolecular crosslinker. Moreover, multivalent host-guest interactions improve the ductility, rapid self-healing and injectable ability of these hydrogels. Simultaneously, these supramolecular hydrogels possess good biocompatibility and can be utilized as carriers for the sustained release of hydrophobic drugs. Thus, such supramolecular hydrogels will have potential applications for tissue engineering and drug delivery systems.

Virus-mimicking mesoporous organosilica nanocapsules with soft framework and rough surface for enhanced cellular uptake and tumor penetration.

An enveloped virus with soft and rough shells has strong penetration ability for cells. Inspired by the unique structure of virus, we successfully constructed virus-mimicking mesoporous organosilica nanocapsules (denoted as VMONs) for the first time by decorating small-sized silica nanoparticles on soft mesoporous organosilica hollow spheres. TEM and SEM images reveal that the prepared VMONs display uniform diameters (240 nm), a soft framework, a rough surface, and excellent dispersity. Quantitative nanomechanical mapping further demonstrates that the VMONs possess an extremely low Young's modulus (36 MPa) and a scraggly surface. In view of the successful construction of the virus-mimicking nanocapsules, the VMONs are further modified with human serum albumin (HSA) and Cy5.5-maleimide (Mal-Cy5.5) to investigate their cell penetration ability. Flow cytometry analysis reveals that the internalization of VMONs@HSA-Cy5.5 increases 2.74-fold compared to that of the conventional mesoporous nanosphere. Confocal laser scanning microscopy images show that the VMONs@HSA-Cy5.5 diffuses deeper for multicellular spheroids compared to both hard and soft mesoporous organosilica nanospheres. The penetration ability of the VMONs and SMONs increases 18.49 and 6.13-fold compared to that of MONs at the depth of 60 µm. Thanks to the excellent cellular penetration ability, the virus-mimicking VMONs@HSA-Cy5.5 can effectively deliver the anticancer drug doxorubicin (Dox) into drug-resistant MCF-7/ADR human breast cancer cells and significantly enhance the chemotherapeutic efficacy. Taken together, the constructed virus-mimicking organosilica nanocapsules with a soft framework and a rough surface possess strong cellular internalization and tumor penetration abilities, providing a unique and effective nanoplatform for biomedical applications.

Overview of stimuli-responsive mesoporous organosilica nanocarriers for drug delivery.

The application of nanomaterials is regarded nowadays as a highly promising approach for overcoming the limitations of the currently available cancer treatments, contributing for the creation of more effective, precise, and safer therapies. In the last years, organosilica nanoparticles arisen as alternatives to the most common mesoporous silica nanoparticles. The organosilica nanoparticles combine the advantages of the mesoporous silica, such as structural stability and mesoporous structure, with the increased biocompatibility and biodegradability of organic materials. Therefore, the variety of organic bridges that can be incorporated into the silica matrix allowed the development of new and exciting compositions, properties, and functions for improving the therapeutic effectiveness of the anticancer nanomedicines. In this review, the strategies that have been explored to create stimuli-responsive organosilica-based drug delivery systems are highlighted, describing the practical approaches and mechanisms controlling the drug release. Additionally, the organosilica nanoparticles surface modifications aimed for increasing the blood circulation time and the tumor targeting are also described.

Effect of m-trifluoromethyl-diphenyl diselenide on acute and subchronic animal models of inflammatory pain: Behavioral, biochemical and molecular insights.

m-Trifluoromethyl-diphenyl diselenide [(m-CF3-PhSe)2] is an organoselenium molecule that displays multiple pharmacological actions, including the antinociceptive effect. The current study investigated the (m-CF3-PhSe)2 restorative properties in models of acute and chronic inflammatory pain induced by complete Freund's adjuvant (CFA). Male adult Swiss mice received an intraplantar injection of CFA in the hindpaw and 24 h (acute) or 14 days (subchronic) later they were treated with a single or repeated (m-CF3-PhSe)2 schedule via intragastric route, respectively. The mechanical and thermal hypernociceptive behaviors were assessed by von Frey hair and hot plate tests. Samples of injected paw were collected to evaluate the tissue edema and myeloperoxidase (MPO) activity while cerebral contralateral cortex samples were used to determine the inflammatory proteins content (subchronic protocol). The acute (m-CF3-PhSe)2 administration (1 and 10 mg/kg) reduced the hypernociceptive behavior and both paw thickness and MPO activity induced by CFA injection. In the subchronic protocol, the repeated administration with a low effective dosage of (m-CF3-PhSe)2 reduced the mechanical and thermal hypernociception as well as restored the edema and MPO activity in paw samples. In addition, the repeated treatment schedule mitigated the increase in TNF-α, IL-1ß and COX-2 content in cerebral contralateral cortex induced by CFA injection. Collectively, these data showed that (m-CF3-PhSe)2 presents anti-inflammatory properties, which could be mediated by an interplay between peripheral and central mechanisms of action, reinforcing the potential biological properties of the compound.

Novel nitric oxide-generating platform using manuka honey as an anti-biofilm strategy in chronic rhinosinusitis.

BACKGROUND: Bacterial biofilms are implicated in the pathogenesis of chronic rhinosinusitis. Nitric oxide (NO) is a key immune effector with potent antimicrobial effects, but a short half-life limits achievement of therapeutic concentrations. We hypothesized that manuka honey (MH) could induce sustained reduction of nitrite to NO causing biofilm disruption and that this effect would be enhanced with the addition of a NO-releasing microparticle. METHODS: Porous organosilica microparticles containing nitrosylated thiol groups were formulated (SNO-MP). MH was combined with serial dilutions of nitrite. NO release was evaluated using a NO analyzer. The susceptibility of 2 strains of Pseudomonas aeruginosa biofilms to these NO-releasing platforms was evaluated using confocal microscopy. Cell viability and biofilm volume were quantified. Statistical analysis was performed using the Mann-Whitney U test with SPSS software. RESULTS: MH with nitrite generated a linear increase in NO formation. SNO-MP induced a bolus release of NO within 5 minutes, followed by a sustained plateau phase. MH with nitrite combined with SNO-MP enhanced NO release during the plateau phase. MH with nitrite reduced biofilm live cells and volume by 88.5% to 96.9% and 95.1% to 95.6%, respectively, vs control (p < 0.0001). SNO-MP reduced live cells and volume by 61.0% to 98.5% and 74.7% to 85.7%, respectively, vs control (p < 0.0001). MH with nitrite combined with SNO-MP nearly eradicated biofilm, with a 98.3% to 99.8% (log 1.8-2.6) reduction in viability and a 91.4% to 97.7% decrease in volume (p < 0.0001 vs control). CONCLUSION: A novel platform that generates NO using MH and nitrite produces a potent anti-biofilm effect, which can be further enhanced with the addition of SNO-MP.

Pharmacokinetic modeling of the blood-stable camptothecin analog AR-67 in two different formulations.

AR-67 is a lipophilic camptothecin analog currently under clinical investigation using a Cremophor EL based formulation. However, as potential toxicity limitations exist in the clinical use of Cremophor, an alternative cyclodextrin (SBE-ß-CD) based formulation has been proposed. Pharmacokinetic (PK) studies were conducted in mice and the SBE-ß-CD based formulation was compared with the Cremophor EL formulation. PK studies were conducted following intravenous or oral administration of AR-67 in either Cremophor or SBE-ß-CD formulation in mice. Noncompartmental analysis was used to determine the plasma and tissue drug distribution. A non-linear mixed effects (population) PK model was developed to fit both the oral and intravenous data and to estimate key PK parameters. The effect of formulation was explored as a covariate in the PK model. AR-67 in the SBE-ß-CD formulation had similar plasma PK and biodistribution to that in the Cremophor EL formulation. The proposed two-compartment model described the plasma PK of AR-67 in both formulations adequately. AR-67 in the SBE-ß-CD formulation exhibited dose linearity following both oral and intravenous administration. Our studies indicate that SBE-ß-CD is a viable alternative to Cremophor EL as a pharmaceutical excipient for formulating AR-67.

Floating molecularly imprinted polymers based on liquid crystalline and polyhedral oligomeric silsesquioxanes for capecitabine sustained release.

Molecularly imprinted polymers (MIPs) have drawn extensive attention as carriers on drug delivery. However, most of MIPs suffer from insufficient drug loading capacity, burst release of drugs and/or low bioavailability. To solve the issues, this study designed an imprinted material with superior floating nature for oral drug delivery system of capecitabine (CAP) rationally. The MIPs was synthesized in the presence of 4-methylphenyl dicyclohexyl ethylene (liquid crystalline, LC) and polyhedral oligomeric silsesquioxanes (POSS) via polymerization reaction. The LC-POSS MIPs had extended release of the template molecules over 13.4 h with entrapment efficiency of 20.53%, diffusion coefficient of 2.83 × 10-11 cm2 s-1, and diffusion exponent of 0.84. Pharmacokinetic studies further revealed the prolong release and high relative bioavailability of CAP in vivo of rats, showing the effective floating effect of the LC-POSS MIPs. The in vivo images revealed visually that the gastroretentive time of the LC-POSS MIPs was longer than non-LC-POSS imprinted polymers. The physical characteristics of the polymers were also characterized by nitrogen adsorption experiment, scanning electron microscopy, thermogravimetric analysis and differential scanning calorimetry analysis. As a conclusion, the LC-POSS MIPs can be used as an eligible CAP carrier and might hold great potential in clinical applications for sustained release drug.

Use of CK-548 and CK-869 as Arp2/3 complex inhibitors directly suppresses microtubule assembly both in vitro and in vivo.

Two types of Arp2/3 complex inhibitors, CK-666/636 and CK-548/869, are commonly used to study Arp2/3 complex-dependent actin assembly both in vitro and in vivo. However, we found that CK-548 and CK-869 directly suppress microtubule (MT) assembly independent of the actin cytoskeleton. Treatment of cultured mammalian cells with 50 µM CK-869 dramatically decreased MT networks and, instead, accumulated tubulin at the cell periphery, as did nocodazole that inhibits MT assembly. An in vitro MT-sedimentation assay revealed that CK-548 and CK-869 significantly suppressed MT polymerization. In budding yeast, although CK-548 and CK-869 are reported to lack binding abilities in the yeast Arp3, CK-548 treatment decreased cytoplasmic MT at several tens of micromolar concentrations. In addition, we found that the effects of CK-548 and CK-869 on MT assembly varied according to species. We propose that CK-548 and CK-869 are not suitable for studying the cytoskeleton in living cells.

An Infrared Dye-Conjugated Virus-like Particle for the Treatment of Primary Uveal Melanoma.

The work outlined herein describes AU-011, a novel recombinant papillomavirus-like particle (VLP) drug conjugate and its initial evaluation as a potential treatment for primary uveal melanoma. The VLP is conjugated with a phthalocyanine photosensitizer, IRDye 700DX, that exerts its cytotoxic effect through photoactivation with a near-infrared laser. We assessed the anticancer properties of AU-011 in vitro utilizing a panel of human cancer cell lines and in vivo using murine subcutaneous and rabbit orthotopic xenograft models of uveal melanoma. The specificity of VLP binding (tumor targeting), mediated through cell surface heparan sulfate proteoglycans (HSPG), was assessed using HSPG-deficient cells and by inclusion of heparin in in vitro studies. Our results provide evidence of potent and selective anticancer activity, both in vitro and in vivo AU-011 activity was blocked by inhibiting its association with HSPG using heparin and using cells lacking surface HSPG, indicating that the tumor tropism of the VLP was not affected by dye conjugation and cell association is critical for AU-011-mediated cytotoxicity. Using the uveal melanoma xenograft models, we observed tumor uptake following intravenous (murine) and intravitreal (rabbit) administration and, after photoactivation, potent dose-dependent tumor responses. Furthermore, in the rabbit orthotopic model, which closely models uveal melanoma as it presents in the clinic, tumor treatment spared the retina and adjacent ocular structures. Our results support further clinical development of this novel therapeutic modality that might transform visual outcomes and provide a targeted therapy for the early-stage treatment of patients with this rare and life-threatening disease. Mol Cancer Ther; 17(2); 565-74. ©2017 AACR.

Charged polyhedral oligomeric silsesquioxanes trigger in vitro METosis via both oxidative stress and autophagy.

AIMS: Monocytes/macrophages are essential in innate immune response against pathogens also because their ability to release extracellular traps named METs (monocytes/macrophages extracellular traps). These structures are composed of DNA fibers decorated with nuclear and cytoplasmic proteins and their production process is called METosis. In this study attention has been focused on the ability of differently charged molecular systems (polyhedral oligomeric silsesquioxanes, POSS positively or negatively charged) to induce METosis. MAIN METHODS: METs formation was induced by lipopolysaccharide (250µg/ml, positive control) and POSS positive and negative (0.05-1mg/ml) treatment. METs were visualized and quantified by confocal microscopy using Sytox green staining. Oxidative stress, autophagy, as well as endocytosis involvement in the POSS induced METosis was evaluated. KEY FINDINGS: Results obtained indicate a POSS positive or negative dose dependent ability in inducing MET release independently to their charge and that this phenomenon is a consequence of POSS +/- internalization. Moreover, studies using many reactive oxidative species (ROS) blockers and autophagy inhibitor showed a strong reduction in POSS induced METosis indicating their involvement. SIGNIFICANCE: POSS +/- induce extracellular traps production in human monocytes/macrophages by oxidative and autophagic pathway.

Tailoring of temperature- and pH-responsive cotton fabric with antimicrobial activity: Effect of the concentration of a bio-barrier-forming agent.

A stimuli-responsive cotton fabric was designed using temperature and pH-responsive poly-N-isopropylacrylamide (poly-NiPAAm) and chitosan (PNCS) microgel as a carrier of antimicrobially active 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (Si-QAC), which forms a bio-barrier on the fibre surface. The influence of Si-QAC on the moisture management and thermoregulation abilities of the PNCS microgel was investigated. Using a pad-dry cure method, Si-QAC was applied to a 100% cotton fabric model in concentrations ranging from 0.05-4% to determine the antimicrobial activity of Si-QAC against two types of bacteria, gram-positive Staphylococcus aureus and gram-negative Escherichia coli. Based on these results, three different concentrations of Si-QAC were selected (0.5, 2 and 4%) and tested with in situ embedment of the agent into PNCS microgel particles for further functionalization of the cotton fabric. The functional properties of the studied samples were assessed by measuring the moisture content, water vapour transmission rate, water uptake and antibacterial activity, and FT-IR and SEM were used to study the chemical and morphological properties of the fibres. The results show that regardless of the concentration, the presence of Si-QAC caused a reduction in the change in the volume of the PNCS microgel particles under conditions that would normally cause swelling. Accordingly, the moisture management and thermoregulation properties of the PNCS microgel were best preserved when the lowest Si-QAC concentration (0.5%) was used. Despite the low concentration, at the conditions required, enough Si-QAC was released from the microgel particles onto the surface of the fibres to form a bio-barrier with excellent antimicrobial activity.

PEGylated Dendrimers as Drug Delivery Vehicles for the Photosensitizer Silicon Phthalocyanine Pc 4 for Candidal Infections.

Fungi account for billions of infections worldwide. The second most prominent causative agent for fungal infections is Candida albicans (C. albicans). As strains of fungi become resistant to antifungal medications, new treatment modalities must be investigated to combat these infections. One approach is to employ photodynamic therapy (PDT). PDT utilizes a photosensitizer, light, and cellular O2 to produce reactive oxygen species (ROS), which then induce oxidative stress resulting in apoptosis. Silicon phthalocyanine Pc 4 is a photosensitizer that has exhibited success in clinical trials for a myriad of skin diseases. The hydrophobic nature of Pc 4, however, poses significant formulation and delivery challenges in the use of this therapy. To mitigate these concerns, a drug delivery vehicle was synthesized to better formulate Pc 4 into a viable PDT agent for treating fungal infections. Utilizing poly(amidoamine) dendrimers as the framework for the vehicle, ∼13% of the amine chain ends were PEGylated to promote water solubility and deter nonspecific adsorption. In vitro studies with C. albicans demonstrate that the potency of Pc 4 was not hindered by the dendrimer vehicle. Encapsulated Pc 4 was able to effectively generate ROS and obliterate fungal pathogens upon photoactivation. The results presented within describe a nanoparticulate delivery vehicle for Pc 4 that readily kills drug-resistant C. albicans and eliminates solvent toxicity, thus, improving formulation characteristics for the hydrophobic photosensitizer.

TIPS pentacene loaded PEO-PDLLA core-shell nanoparticles have similar cellular uptake dynamics in M1 and M2 macrophages and in corresponding in vivo microenvironments.

Nanoparticle based drug delivery platforms have the potential to transform disease treatment paradigms and therapeutic strategies, especially in the context of pulmonary medicine. Once administered, nanoparticles disperse throughout the lung and many are phagocytosed by macrophages. However, there is a paucity of knowledge regarding cellular up-take dynamics of nanoparticles due largely to macrophage heterogeneity. To address this issue, we sought to better define nanoparticle up-take using polarized M1 and M2 macrophages and novel TIPS-pentacene loaded PEO-PDLLA nanoparticles. Our data reveal that primary macrophages polarized to either M1 or M2 phenotypes have similar levels of nanoparticle phagocytosis. Similarly, M1 and M2 polarized macrophages isolated from the lungs of mice following either acute (Th1) or allergic (Th2) airway inflammation also demonstrated equivalent levels of nanoparticle up-take. Together, these studies provide critical benchmark information pertaining to cellular up-take dynamics and biodistribution of nanoparticles in the context of clinically relevant inflammatory microenvironments.

A Biodesigned Nanocomposite Biomaterial for Auricular Cartilage Reconstruction.

Current biomaterials for auricular replacement are associated with high rates of infection and extrusion. The development of new auricular biomaterials that mimic the mechanical properties of native tissue and promote desirable cellular interactions may prevent implant failure. A porous 3D nanocomposite scaffold (NS) based on POSS-PCU (polyhedral oligomeric silsesquioxane nanocage into polycarbonate based urea-urethane) is developed with an elastic modulus similar to native ear. In vitro biological interactions on this NS reveal greater protein adsorption, increased fibroblast adhesion, proliferation, and collagen production compared with Medpor (the current synthetic auricular implant). In vivo, the POSS-PCU with larger pores (NS2; 150-250 µm) have greater tissue ingrowth (≈5.8× and ≈1.4 × increase) than the POSS-PCU with smaller pores (NS1; 100-50 µm) and when compared to Medpor (>100 µm). The NS2 with the larger pores demonstrates a reduced fibrotic encapsulation compared with NS1 and Medpor (≈4.1× and ≈1.6×, respectively; P < 0.05). Porosity also influences the amount of neovascularization within the implants, with no blood vessel observed in NS1 (12 weeks postimplantation). The lack of chronic inflammatory response for all materials may indicate that the elastic modulus and pore size of the implant scaffold could be important design considerations for influencing fibrotic responses to auricular and other soft tissue implants.

EGFR targeted nanobody-photosensitizer conjugates for photodynamic therapy in a pre-clinical model of head and neck cancer.

Photodynamic therapy (PDT) induces cell death through local light activation of a photosensitizer (PS) and has been used to treat head and neck cancers. Yet, common PS lack tumor specificity, which leads to collateral damage to normal tissues. Targeted delivery of PS via antibodies has pre-clinically improved tumor selectivity. However, antibodies have long half-lives and relatively poor tissue penetration, which could limit therapeutic efficacy and lead to long photosensitivity. Here, in this feasibility study, we evaluate at the pre-clinical level a recently introduced format of targeted PDT, which employs nanobodies as targeting agents and a water-soluble PS (IRDye700DX) that is traceable through optical imaging. In vitro, the PS solely binds to cells and induces phototoxicity on cells overexpressing the epidermal growth factor receptor (EGFR), when conjugated to the EGFR targeted nanobodies. To investigate whether this new format of targeted PDT is capable of inducing selective tumor cell death in vivo, PDT was applied on an orthotopic mouse tumor model with illumination at 1h post-injection of the nanobody-PS conjugates, as selected from quantitative fluorescence spectroscopy measurements. In parallel, and as a reference, PDT was applied with an antibody-PS conjugate, with illumination performed 24h post-injection. Importantly, EGFR targeted nanobody-PS conjugates led to extensive tumor necrosis (approx. 90%) and almost no toxicity in healthy tissues, as observed through histology 24h after PDT. Overall, results show that these EGFR targeted nanobody-PS conjugates are selective and able to induce tumor cell death in vivo. Additional studies are now needed to assess the full potential of this approach to improving PDT.