Label-free electrochemical biosensor for direct detection of Oncostatin M (OSM) inflammatory bowel diseases (IBD) biomarker in human serum

Oncostatin M (OSM) is an interleukin-6 (IL-6) member family cytokine implicated in the pathogenesis of chronic diseases including inflammatory bowel disease (IBD). OSM is a novel diagnostic biomarker over-expressed in the serum of IBD patients. This paper reports on the first electrochemical OSM immunosensor, developed using a multistep fabrication process aimed at covalently immobilizing OSM antibodies on a mixed self-assembled monolayer coated gold working electrode. Cyclic voltammetry, atomic force microscopy (AFM), IR spectroscopy and optical characterizations were used to validate the sensor functionalization protocol. Electrochemical impedance spectroscopy (EIS) measurements were performed to assess the reliability of the immunosensor preparation and to verify the antibody-antigen complexes formation. The label-free immunosensor showed high sensitivity identifying OSM at clinically relevant concentrations (37-1000 pg mL-1) with low detection limit of 2.86 pg mL-1. Both sensitivity and selectivity of the proposed immunosensor were also demonstrated in human serum in the presence of interfering biomarkers, making it an innovative potential platform for the OSM biomarker detection in IBD patients' serum.

Anthracycline-related cardiotoxicity in patients with breast cancer harboring mutational signature of homologous recombination deficiency (HRD)

BACKGROUND

The BRCA proteins play a key role in the homologous recombination (HR) pathway. Beyond BRCA1/2, other genes are involved in the HR repair (HRR). Due to the prominent role in the cellular repair process, pathogenic or likely pathogenic variants (PV/LPVs) in HRR genes may cause inadequate DNA damage repair in cardiomyocytes.

PATIENTS AND METHODS

This was a multicenter, hospital-based, retrospective cohort study to investigate the heart toxicity from anthracycline-containing regimens (ACRs) in the adjuvant setting of breast cancer (BC) patients carrying germline BRCA PV/LPVs and no-BRCA HRR pathway genes. The left ventricular ejection fraction (LVEF) was assessed using cardiac ultrasound before starting ACR therapy and at subsequent time points according to clinical indications.

RESULTS

Five hundred and three BC patients were included in the study. We predefined three groups: (i) BRCA cohort; (ii) no-BRCA cohort; (iii) variant of uncertain significance (VUS)/wild-type (WT) cohort. When baseline (T0) and post-ACR (T1) LVEFs between the three cohorts were compared, pre-treatment LVEF values were not different (BRCA1/2 versus HRR-no-BRCA versus VUS/WT cohort). Notably, during monitoring (T1, median 3.4 months), patients carrying BRCA or HRR no-BRCA germline pathogenic or likely pathogenic variants showed a statistically significant reduction of LVEF compared to baseline (T0). To assess the relevance of HRR on the results, we included the analysis of the subgroup of 20 BC patients carrying PV/LPVs in other genes not involved in HRR, such as mismatch repair genes (MUTYH, PMS2, MSH6). Unlike HRR genes, no significant differences in T0-T1 were found in this subgroup of patients.

CONCLUSION

Our data suggest that deleterious variants in HRR genes, leading to impaired HR, could increase the sensitivity of cardiomyocytes to ACR in early BC patients. In this subgroup of patients, other measurements, such as the global longitudinal strain, and a more in-depth assessment of risk factors may be proposed in the future to optimize cardiovascular risk management and improve long-term survival.

Nutritional management of the patient with pancreatic cancer: from the diagnostic and therapeutic pathway to an integrated hospital-territory approach

Abstract

Pancreatic cancer is associated to a high risk of malnutrition and neoplastic cachexia even at first diagnosis. Malnutrition is a negative prognostic factor for the outcome of surgery or medical oncology treatments. Despite the good awareness of the problem and the knowledge of the guidelines, the early recognition of malnutrition and its management are still uneven, mainly due to the lack of implementation of standardized and shared protocols and the shortage of dedicated clinical nutritionists and dieticians. An early and appropriate nutritional intervention is mandatory to improve the outcome of patients with pancreatic cancer at any stage of disease. The Mini Nutritional Assessment is useful tool to screen patients malnourished or at risk of malnutrition. The need for the establishment and implementation of an integrated hospital - territorial assistance as well as a home-delivered nutrition service is discussed.

TEER and Ion Selective Transwell-Integrated Sensors System for Caco-2 Cell Model

Monitoring of ions in real-time directly in cell culture systems and in organ-on-a-chip platforms represents a significant investigation tool to understand ion regulation and distribution in the body and ions' involvement in biological mechanisms and specific pathologies. Innovative flexible sensors coupling electrochemical stripping analysis (square wave anodic stripping voltammetry, SWASV) with an ion selective membrane (ISM) were developed and integrated in Transwell™ cell culture systems to investigate the transport of zinc and copper ions across a human intestinal Caco-2 cell monolayer. The fabricated ion-selective sensors demonstrated good sensitivity (1 × 10^-11 M ion concentration) and low detection limits, consistent with pathophysiological cellular concentration ranges. A non-invasive electrochemical impedance spectroscopy (EIS) analysis, in situ, across a selected spectrum of frequencies (10-10⁵ Hz), and an equivalent circuit fitting were employed to obtain useful electrical parameters for cellular barrier integrity monitoring. Transepithelial electrical resistance (TEER) data and immunofluorescent images were used to validate the intestinal epithelial integrity and the permeability enhancer effect of ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) treatment. The proposed devices represent a real prospective tool for monitoring cellular and molecular events and for studies on gut metabolism/permeability. They will enable a rapid integration of these sensors into gut-on-chip systems.

Poly(l-lactide-co-caprolactone-co-glycolide)-Based Nanoparticles as Delivery Platform: Effect of the Surfactants on Characteristics and Delivery Efficiency

Polymeric nanoparticles made of the copolymer Poly(L-lactide-co-caprolactone-co-glycolide) were prepared using the solvent evaporation method. Two different surfactants, polyvinyl alcohol and dextran, and a mixture of the two were employed. The three types of nanoparticles were used as hosting carriers of two chemotherapeutic drugs, the hydrophilic doxorubicin and the hydrophobic SN-38. The morphostructural characterization showed similar features for the three types of nanoparticles, while the drug encapsulation efficiency indicated that the dextran-based systems are the most effective with both drugs. Cellular studies with breast cancer cells were performed to compare the delivery capability and the cytotoxicity profile of the three nanosystems. The results show that the unloaded nanoparticles are highly biocompatible at the administered concentrations and confirmed that dextran-coated nanoparticles are the most efficient vectors to release the two drugs, exerting cytotoxic activity. PVA, on the other hand, shows limited drug release in vitro, probably due to strong interactions with both drugs. Data also show the release is more efficient for doxorubicin than for SN-38; indeed, the doxorubicin IC₅₀ value for the dextran-coated nanoparticles was about 35% lower than the free drug. This indicates that these nanocarriers are suitable candidates to deliver hydrophilic drugs while needing further modification to host hydrophobic molecules.

How Microgels Can Improve the Impact of Organ-on-Chip and Microfluidic Devices for 3D Culture: Compartmentalization, Single Cell Encapsulation and Control on Cell Fate

The Organ-on-chip (OOC) devices represent the new frontier in biomedical research to produce micro-organoids and tissues for drug testing and regenerative medicine. The development of such miniaturized models requires the 3D culture of multiple cell types in a highly controlled microenvironment, opening new challenges in reproducing the extracellular matrix (ECM) experienced by cells in vivo. In this regard, cell-laden microgels (CLMs) represent a promising tool for 3D cell culturing and on-chip generation of micro-organs. The engineering of hydrogel matrix with properly balanced biochemical and biophysical cues enables the formation of tunable 3D cellular microenvironments and long-term in vitro cultures. This focused review provides an overview of the most recent applications of CLMs in microfluidic devices for organoids formation, highlighting microgels' roles in OOC development as well as insights into future research.

Lipid-Based Nanovesicles for Simultaneous Intracellular Delivery of Hydrophobic, Hydrophilic, and Amphiphilic Species

Lipid nanovesicles (NVs) are the first nanoformulation that entered the clinical use in oncology for the treatment of solid tumors. They are indeed versatile systems which can be loaded with either hydrophobic or hydrophilic molecules, for both imaging and drug delivery, and with high biocompatibility, and limited immunogenicity. In the present work, NVs with a lipid composition resembling that of natural vesicles were prepared using the ultrasonication method. The NVs were successfully loaded with fluorophores molecules (DOP-F-DS and a fluorescent protein), inorganic nanoparticles (quantum dots and magnetic nanoparticles), and anti-cancer drugs (SN-38 and doxorubicin). The encapsulation of such different molecules showed the versatility of the developed systems. The size of the vesicles varied from 100 up to 300 nm depending on the type of loaded species, which were accommodated either into the lipid bilayer or into the aqueous core according to their hydrophobic or hydrophilic nature. Viability assays were performed on cellular models of breast cancer (MCF-7 and MDA-MB-231). Results showed that NVs with encapsulated both drugs simultaneously led to a significant reduction of the cellular activity (up to 22%) compared to the free drugs or to the NVs encapsulated with only one drug. Lipidomic analysis suggested that the mechanism of action of the drugs is the same, whether they are free or encapsulated, but administration of the drugs by means of nanovesicles is more efficient in inducing cellular damage, likely because of a quicker internalization and a sustained release. This study confirms the versatility and the potential of lipid NVs for cancer treatment, as well as the validity of the ultrasound preparation method for their preparation.

Nivolumab in metastatic melanoma: good efficacy and tolerability in elderly patients

Background

Nivolumab is an anti-PD-1 antibody that restores the antitumour immune function of T cells, blocking the binding of PD-1 with its ligand PD-L1. PD-1 is expressed on T cells and interacts with PD-L1 on tumour cells. The PD-1-PD-L1 link inhibits T cell activation. In metastatic melanoma, PD-1-PD-L1 binding plays a critical role, and the advent of the immune checkpoint inhibitor nivolumab has delivered new and effective treatment options with proven clinical benefit. In the present study, we evaluated the efficacy of nivolumab in elderly patients with metastatic melanoma.

Methods

The study enrolled 55 elderly patients (75 years of age and older) with a diagnosis of metastatic melanoma. Primary endpoints of the study were progression-free survival (pfs) and the objective response rate; secondary endpoints were overall survival, reduction in serum lactate dehydrogenase (ldh) from before to after treatment, and tolerability.

Results

Nivolumab was well tolerated and resulted in good disease control, with a manageable toxicity profile and significant clinical benefit. The duration of pfs was 5.1 months (95% confidence interval: 3.5 months to 6.8 months). A significant correlation was observed between reduction in serum ldh and pfs: 0.60 (95% confidence interval: 0.28 to 0.86; p = 0.002).

Conclusions

Nivolumab is an immunotherapy treatment that has proved to be an effective and well-tolerated therapeutic option in elderly patients with metastatic melanoma.

Piezoelectricity and Biocompatibility of Flexible ScxAl(1-x)N Thin Films for Compliant MEMS Transducers

There is huge research activity in the development of flexible and biocompatible piezoelectric materials for next-generation compliant micro electro-mechanical systems (MEMS) transducers to be exploited in wearable devices and implants. This work reports for the first time on the development of flexible Sc_xAl_(1-x)N films deposited by sputtering technique onto polyimide substrates, assessing their piezoelectricity and biocompatibility. Flexible Sc_xAl_(1-x)N films have been analyzed in terms of morphological, structural, and piezoelectric properties. Sc_xAl_(1-x)N layer exhibits a good surface roughness of 4.40 nm and moderate piezoelectricity with an extracted effective piezoelectric coefficient (d₃₃^eff) value of 1.87 ± 0.06 pm/V, in good agreement with the diffraction pattern analysis results. Cell viability assay, performed to study the interaction of the Sc_xAl_(1-x)N films with human cell lines, shows that this material does not have significant effects on tested cells. Furthermore, the Sc_xAl_(1-x)N layer, integrated onto a flexible device and analyzed by bending/unbending measurements, shows a peak-to-peak open-circuit voltage (V_OC) of 0.32 V and a short-circuit current (I_SC) of 0.27 μA, with a generated power of 19.28 nW under optimal resistive load, thus demonstrating the potential of flexible Sc_xAl_(1-x)N films as active layers for next-generation wearable/implantable piezoelectrics.

Novel synthesis of platinum complexes and their intracellular delivery to tumor cells by means of magnetic nanoparticles

Platinum-based drugs are popular in clinics as chemotherapeutic agents to treat solid tumors. However, severe side effects such as nephro- and neurotoxicity impose strict dosage limitations that can lead to the development of drug resistance and tumor relapse. To overcome these issues Pt(iv) prodrugs and platinum delivery systems might represent the next generation of platinum-based drugs. In this study four novel Pt(ii) complexes (namely, PEG-Glu-Pt-EDA, PEG-Glu-Pt-DACH, PEG-Mal-Pt-EDA and PEG-Mal-Pt-DACH) were synthesized and a general strategy to covalently bind them to iron oxide nanoparticles was developed. The intracellular uptake and cell distribution studies of Pt-tethered magnetic nanoparticles on breast and ovarian cancer cell line models indicate that binding of the Pt complexes to the nanoparticles facilitates, for all the complexes, cellular internalization. Moreover, the magnetic nanoparticles (MNPs), as shown in a magnetofection experiment, enhance the uptake of MNP-Pt conjugates if a magnet is placed beneath the culture dish of tumor cells. As shown by a Pt release experiment, intranuclear platinum quantification and TEM analysis on cell sections, the presence of a pH-sensitive dicarboxylic group coordinating the Pt complex, triggers platinum dissociation from the NP surface. In addition, the triazole moiety facilitates endosomal swelling and the leakage of platinum from the endosomes with intranuclear localization of platinum release by the NPs. Finally, as assessed by MTT, caspase, calcein/ethidium bromide live/dead assays, among the four NP-Pt conjugates, the NP-Glu-Pt-EDA complex having a glutamate ring and ethylenediamine as a chelating amine group of the platinum showed higher cytotoxicity than the other three MNP-platinum conjugates.

Abstract P4-13-04: Not presented

This abstract was not presented at the conference.

Citation Format: Cazzaniga ME, Blasi L, Pronzato P, Giordano M, Garrone O, Donadio M, Del Mastro L, Livi L, Natoli C, Michelotti A, Turletti A, Riccardi F, De Laurentiis M, Marchetti P, Montemurro F, Romagnoli E, De Placido S, Biganzoli L, Bologna A, Bria E, Mustacchi G. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-13-04.

Abstract P1-14-04: Overall survival in metastatic breast cancer patients in the third millennium: Results of an Italian study

BACKGROUND - Metastatic breast cancer (MBC) is a life-threatening disease. It is important to provide data about real-life MBC patients (pts) to understand the current prognostic factors. The aim of the present observational study, named COSMO (Checking Overall Survival in a MBC Observational study) is to describe the overall survival (OS) in a large cohort of MBC pts, assessing its correlation with specific prognostic factors (demographic, clinic, pathologic and biological).

PATIENTS AND METHODS - The COSMO study is a multicenter, retrospective, cohort study, developed throughout the collaboration of 31 Italian oncological centers. Data about pts diagnosed as metastatic from 01/01/2000 to 31/12/2008, were collected. The association between molecular subtypes, metastatic sites, disease free interval (DFI) and OS were assessed. Pts were classified in three subgroups, based on the biological characteristics of their tumor: luminal, HER2-positive (regardless of hormone receptor) and triple negative (TN). Metastatic sites were categorized as visceral versus non-visceral disease, only bone and central nervous system (CNS) metastases. DFI was calculated from diagnosis to first relapse only for M0 pts.

RESULTS - Of 3931 MBC pts enrolled in the study, 3720 were evaluable, with a median age of 61 years (interquartile range, IQR, 51-71). 1804 (62,1%) pts had a luminal disease, 691 (23,8%) HER2-positive, 410 (14.1%) TN. Median DFI was 3.2 years (IQR 1.7- 6.0). Regarding metastatic sites, pts with visceral disease were 2332 (63%); 826 (22,2%) pts had bone isolated metastases; in 306 (8,3%) pts, CNS metastases were reported. With a median follow up of 9 years (IQR 5.7-11.0) and 3098 (83.3%) recorded events, we founded a median OS of 2.8 years (95%CI: 2.7-2.9) years. OS was strictly depending from molecular subtypes with a better prognosis for HER2-positive versus luminal and TN MBC pts, median OS of 3.1 (95%CI 2.8-3.4), 3.0 (95%CI: 2.9-3.1) and 1.5 (95%CI: 1.3-1.7) years respectively (p-value<0.001). 525 (14,1%) pts received trastuzumab. Metastatic sites affect prognosis, with a better OS for bone disease (3.4 years, 95%CI: 3.1-3.6) versus visceral disease (2.2 years 95%CI: 2.0- 2.3). Brain metastasis correlate with the worst prognosis: OS of 1.5 years (95% CI: 0.8 – 1.7). Even DFI shows a correlation with prognosis: pts with DFI>2 years show a median OS of 3 years (95% CI: 2.9 – 3.2), while those with DFI<2 years have a median OS of 2.4 years (95% CI: 2.3-2.6); HR was 0.69 (95%CI: 0,62-0,76) for every five years of increase in DFI (p-value<0.001).

CONCLUSIONS - Molecular subtype is crucial for prognosis: HER2-positive subtype has the best prognosis, while TN subtype has the shorter OS. Having a longer DFI from diagnosis (>2 years) correlate with a better prognosis. Our study confirm that sites of metastasis affects outcome: visceral involvement correlates with poor prognosis and, particularly, pts with brain metastasis represent the worst subgroup, while pts with solely bone disease have the best prognosis. The COSMO study provides a view on the Italian landscape of MBC between 2000 and 2008, adding new insights about pts prognosis.

Citation Format: La Verde N, Collovà E, Blasi L, Pinotti G, Bernardo A, Bonotto M, Garrone O, Brunello A, Cavazzini MG, Bareggi C, Prochilo T, Porcu L, Moretti A, Barni S, On Behalf of COSMO Study Group. Overall survival in metastatic breast cancer patients in the third millennium: Results of an Italian study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-14-04.

Efficacy and safety of Everolimus and Exemestane in hormone-receptor positive (HR+) human-epidermal-growth-factor negative (HER2-) advanced breast cancer patients: New insights beyond clinical trials. The EVA study

BACKGROUND

The BOLERO-2 trial reported efficacy and safety of Everolimus (EVE) and Exemestane (EXE) combination in HR+ advanced breast cancer (ABC) patients. The BALLET trial further evaluated the safety of EVE-EXE in HR+ ABC patients, without reporting efficacy data. Aim of the EVA real-life study was to collect data of efficacy and safety of EVE-EXE combination in the clinical setting, as well as exploring efficacy according to EVE Dose-Intensity (DI) and to previous treatment with Fulvestrant.

PATIENTS AND METHODS

This study aimed to describe the outcome of ABC pts treated with EVE-EXE combination in terms of median duration of EVE treatment and ORR in a real-life setting.

RESULTS

From July 2013 to December 2015, the EVA study enrolled 404 pts. Median age was 61 years (33-83). Main metastatic sites were: bone (69.1%), soft tissue (34.7%) and viscera (33.2%). Median number of previous treatments was 2 (1-7). 43.3% of the pts had received Fulvestrant. Median exposure to EVE was 31.0 weeks (15.4-58.3) in the whole population. No difference was observed in terms of EVE exposure duration according to DI (p for trend = 0.27) or type of previous treatments (p = 0.33). ORR and Disease Control Rate (DCR) were observed in 31.6% and 60.7% of the patients, respectively, with the lowest ORRs confined in CHT pre-treated patients or in those who received the lowest DI of EVE. Grade 3-4 adverse events (AEs) were reported in 37.9% of the patients. Main AEs were: stomatitis (11.2%), non-infectious pneumonitis - NIP (3.8%), anaemia (3.8%) and fatigue (3.2%).

CONCLUSIONS

The EVA study provided new insights in the use of EVE-EVE combination in HR+ ABC pts many years after the publication of the pivotal trial. The combination is safe and the best response could be obtained in patients receiving the full dose of EVE and/or after hormone-therapy as Fulvestrant in ABC.

A 2D approach to surface-tension-confined fluidics on parylene C

Parylene C-based 2D STC fluidics, where pure water and water-based solutions can flow strictly confined by differences in surface energy.

Exploiting Photo- and Electroluminescence Properties of FIrpic Organic Crystals

In this work, we investigate the optical and structural properties of the well-known triplet emitter bis(4',6'-difluorophenylpyridinato)-iridium(III) picolinate (FIrpic), showing that its ability to pack in two different ordered crystal structures promotes attractive photophysical properties that are useful for solid-state lighting applications. This approach allows the detrimental effects of the nonradiative pathways on the luminescence performance in highly concentrated organic active materials to be weakened. The remarkable electro-optical behavior of sky-blue phosphorescent organic light-emitting diodes incorporating crystal domains of FIrpic, dispersed into an appropriate matrix as an active layer, has also been reported as well as the X-ray diffraction, nuclear magnetic resonance, electro-ionization mass spectrometry, and scanning electron microscopy analyses of the crystalline samples. We consider this result as a crucial starting point for further research aimed at the use of a crystal triplet emitter in optoelectronic devices to overcome the long-standing issue of luminescence self-quenching.

Fibrous scaffolds fabricated by emulsion electrospinning: from hosting capacity to in vivo biocompatibility

Electrospinning is a versatile method for preparing functional three-dimensional scaffolds. Synthetic and natural polymers have been used to produce micro- and nanofibers that mimic extracellular matrices. Here, we describe the use of emulsion electrospinning to prepare blended fibers capable of hosting aqueous species and releasing them in solution. The existence of an aqueous and a non-aqueous phase allows water-soluble molecules to be introduced without altering the structure and the degradation of the fibers, and means that their release properties under physiological conditions can be controlled. To demonstrate the loading capability and flexibility of the blend, various species were introduced, from magnetic nanoparticles and quantum rods to biological molecules. Cellular studies showed the spontaneous adhesion and alignment of cells along the fibers. Finally, in vivo experiments demonstrated the high biocompatibility and safety of the scaffolds up to 21 days post-implantation.

New biocompatible polymeric micelles designed for efficient intracellular uptake and delivery

New amphiphilic block copolymers are easily synthesised by post-polymerisation modifications of poly(glycidyl methacrylate) chain derivatives. The obtained material, upon dispersion in water, is capable of self-assembling into robust micelles. These nanoparticles, which are also characterised by adaptable stability, were loaded with different thiophene based fluorophores. The photoluminescent micelles were administered to cultured cells revealing a high and rapid internalisation of structurally different fluorescent molecules by the same internalisation pathway. Appropriate pairs of chromophores were selected and loaded into the micelles to induce Förster resonance energy transfer (FRET). The disappearing of the FRET phenomenon, after cell uptaking, demonstrated the intracellular release of the nanoparticle contents. The studied nanomaterial and the loaded chromophores have also shown to be biocompatible and non toxic towards the tested cells.

[Long-term survival metastatic ovarian cancer elderly patient]

Ovarian cancer is the sixth diagnosed cancer among women worldwide, it has a high mortality and in most cases it's diagnosed in advanced stage (stage III-IV). Combination platinum-paclitaxel chemotherapy administered every 3 weeks is considered the gold standard for first-line treatment of patients with advanced ovarian cancer. Elderly patients with ovarian cancer represents a subgroup with poor prognosis because they are often treated less radically for comorbidities and age. In the present article, we report a case of a 85 year old woman who was diagnosed with stage IV ovarian carcinoma for the presence of peritoneal carcinomatosis ab initio, not radically debulked and then treated with weekly schedule platinum-based and paclitaxel. Despite not being able to complete the chemotherapy, the patient achieved excellent results and represents a case of long survival.

Parylene C surface functionalization and patterning with pH-responsive microgels

Parylene C is a polymer well-known for its inertness and chemical resistance, thus ideal for covering and sealing 3D substrates and structures by conformal coating. In the present study, the Parylene C surface is modified by functionalization with pH-responsive poly(methacrylic acid) microgels either over the whole surface, or in a pattern through a poly(dimethylsiloxane) stamp. The surface functionalization consists of two phases: first, an oxygen plasma treatment is used to make the surface superhydrophilic, inducing the formation of polar functional groups and surface topography modifications; then, the plasma-treated samples are functionalized by drop casting a solution of pH-responsive microgels, or in a pattern via microcontact printing of the same solution. While both techniques, namely, drop casting and microcontact printing, are easy to use, fast, and cheap, the microcontact printing was found to provide a more homogeneous functionalization and to be applicable to any shape of substrate. The functionalization effectiveness was tested by the repeated uptake and release of a fluorescent labeled monoclonal CD4 antibody at different pH values, thus suggesting a new sensing approach.

Enzyme-responsive multifunctional surfaces for controlled uptake/release of (bio)molecules

The current trend in the development of biomaterials is towards bioactive and biodegradable systems. In particular, enzyme-responsive structures are useful tools to realize biodegradable surfaces for the controlled delivery of biomolecules/drugs through a triggered surface erosion process. Up to now, enzyme-responsive structures have been designed by covalent linkage between synthetic polymers and biodegradable functionalities that are responsive to chemical and biological cues (i.e. proteases or pH) [1-4]. Here, we present a novel approach to achieve enzyme-responsive surface-attached networks by exploiting the non-covalent interaction between streptavidin and biotin. The functional component of this three-dimensional (3D) structure is a layer of biotinylated peptides that are degraded by the action of specific proteases. The system was stable under typical physiological conditions; however, it was efficiently degraded upon enzyme exposure. Further, the controlled release of biomolecules and drugs--previously entrapped into the surface-attached network--was demonstrated to occur as a consequence of the enzymatic cleavage. This versatile approach does not require complex chemical procedures. Interestingly, it can be easily adapted to different enzyme-peptide partners and therefore is very attractive for tissue replacement, drug delivery and biosensing.

pH controlled staining of CD4(+) and CD19(+) cells within functionalized microfluidic channel

Herein proposed is a simple system to realize hands-free labeling and simultaneous detection of two human cell lines within a microfluidic device. This system was realized by novel covalent immobilization of pH-responsive poly(methacrylic acid) microgels onto the inner glass surface of an assembled polydimethylsiloxane/glass microfluidic channel. Afterwards, selected thiophene labeled monoclonal antibodies, specific for recognition of CD4 antigens on T helper/inducer cells and CD19 antigens on B lymphocytes cell lines, were encapsulated in their active state by the immobilized microgels. When the lymphocytes suspension, containing the two target subpopulations, was flowed through the microchannel, the physiological pH of the cellular suspension induced the release of the labeled antibodies from the microgels and thus the selective cellular staining. The selective pH-triggered staining of the CD4- and CD19-positive cells was investigated in this preliminary experimental study by laser scanning confocal microscopy. This approach represents an interesting and versatile tool to realize cellular staining in a defined module of lab-on-a-chip devices for subsequent detection and counting.

In situ formation and size control of gold nanoparticles into chitosan for nanocomposite surfaces with tailored wettability

The in situ formation of gold nanoparticles into the natural polymer chitosan is described upon pulsed laser irradiation. In particular, hydrogel-type films of chitosan get loaded with the gold precursor, chloroauric acid salt (HAuCl(4)), by immersion in its aqueous solution. After the irradiation of this system with increasing number of ultraviolet laser pulses, we observe the formation of gold nanoparticles with increasing density and decreasing size. Analytical studies using absorption measurements, atomic force microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy of the nanocomposite samples throughout the irradiation procedure reveal that under the specific irradiation conditions there are two competing mechanisms responsible for the nanoparticles production: the photoreduction of the precursor responsible for the rising growth of gold particles with increasing size and the subsequent photofragmentation of these particles into smaller ones. The described method allows the localized formation of gold nanoparticles into specific areas of the polymeric films, expanding its potential applications due to its patterning capability. The size and density control of the gold nanoparticles, obtained by the accurate increase of the laser irradiation time, is accompanied by the simultaneously controlled increase of the wettability of the obtained gold nanocomposite surfaces. The capability of tailoring the hydrophilicity of nanocomposite materials based on natural polymer and biocompatible gold nanoparticles provides new potentialities in microfluidics or lab on chip devices for blood analysis or drugs transport, as well as in scaffold development for preferential cells growth.

Nanowalled polymer microtubes fabricated by using strained semiconductor templates

Herein we describe the realization of nanowalled polymeric microtubes through a novel and versatile approach combining the layer-by-layer (LbL) deposition technique, the self-rolling of hybrid polymer/semiconductor microtubes and the subsequent removal of the semiconductor template. The realized channels were characterized in detail using scanning electron and atomic force microscopes. Additionally, we report on the incorporation of a dye molecule within the nanowalls of such microtubes, demonstrating a distribution of the fluorescence signal throughout the whole channel volume. This approach offers the possibility to tailor the properties of micro/nanotubes in terms of size, wall thickness and composition, thus enabling their employment for several applications.

Uptake and distribution of labeled antibodies into pH-sensitive microgels

We investigated the uptake and release of labeled antibodies from pH-sensitive hydrogel microparticles (i.e. microgels) by means of fluorescence analysis of labeled biological samples. The poly(methacrylic acid) (PMAA) hydrogel is a carbon-based network having carboxylic groups on the surface that dissociate according to their acid-base equilibrium. The ability of the PMAA microgel to encapsulate and release anti-CD4 and anti-CD8 monoclonal antibodies (MAbs), differing for the isotype and labeled with highly photostable fluorophore, was studied in solution by photoluminescence spectroscopy. The experimental results indicated that the uptake and release of the tested antibodies were controlled by pH. Furthermore, confocal microscopy analysis in the solid state revealed that the distribution of the labeled antibodies either on the surface or in the core of the microgel matrix was related to the specific properties of these MAbs.

New biweekly combination of trastuzumab, docetaxel, and gemcitabine for HER2-positive metastatic breast cancer: First early results from a phase II multicentric trial on behalf of Gruppo Oncologico Italia Meridionale

1096

Background: The clinical activity of the combination of chemotherapy plus trastuzumab in HER-2 overexpressing metastatic breast cancer has been well documentated. We report the first results in terms of efficacy and safety of a phase II trial on biweekly combination of trastuzumab plus docetaxel and gemcitabine as first line therapy in HER-2-positive metastatic breast cancer patients. Methods: Patients at first relapse or with synchronous metastasis, were treated with trastuzumab (4 mg/kg, loading dose 6 mg/kg) plus gemcitabine (1000 mg/m2) plus docetaxel (50 mg/m2) as biweekly schedule. Primary end-point was overall response rate (ORR), secondary end-point time to progression (TTP), clinical benefit rate (CBR; PR+ CR + prolonged SD for ≥ 24 weeks), and tolerability. Based on previous data, an ORR greater than 60% was considered to indicate clinical activity in this two stage design trial. Results: A total of 26 patients with histologically confirmed, measurable MBC, tumors scored as +3 positive for HER-2 by immuno-histochemistry or FISH +, no pretreated with chemotherapy or trastuzumab for metastatic disease have been enrolled, 22 actually evaluable for response and toxicity. Median age was 49 years (range 34–66), visceral metastases were present in most patients (73%). Median number of cycles was 8 (range 3–12). The ORR was 86% (95% CI, 80–91%), with two CR (9 %) and 17 PR (77%). 3 patients had SD, 1 prolonged (14%). The CBR was 91% (95% CI, 87%-94%). No progression of disease was observed. Median TTP was 7 months (range 5- 9+ months). The worst toxicity was WHO grade 2 neutropenia and grade 2 gastric pain. Conclusions: In this phase II study, the biweekly combination of trastuzumab, gemcitabine, and docetaxel in HER-2-positive breast cancer is very active. The toxicity observed was manageable and did not lead to treatment discontinuation. Thus, the patients accrual is ongoing to the preset target of 50 patients.

No significant financial relationships to disclose.

Self-assembling of proteins and enzymes at nanoscale for biodevice applications

Different nanotechnological strategies have been selected to implement biomolecular devices following a bottom-up or top-down approach depending on the biomolecule and on its functionality. Biomolecules have particular functionality and self-assembling capabilities that can be exploited for the implementation of both bioelectronic devices and multipurpose engineered biosurfaces. Surface preparation with supramolecular methods and microcontact printing have been developed and optimised to realise suitable functionalised surfaces. These surfaces can be used to link metalloproteins and enzymes for the implementation of nanobioelectronic devices and planar biosensors or to bind cells in order to promote their growth along predefined tracks and grooves. Some possible applications of these biosurfaces are shown and discussed. Results are presented for the realisation of a biomolecular nanodevice working in air based on the metalloprotein azurin immobilised in the solid state, the formation and characterisation of functional glutamate Dehydrogenase monolayers for nanobiosensing applications, the results of soft lithography processes on azurin for biosensor implementation, and the development of physiological self-assembled patterns of laminin-1 for cell culture applications and hybrid devices.

Study of the surface morphology of a cholesteryl tethering system for lipidic bilayers

The immobilization of functional molecules embedded in lipidic membranes onto inorganic substrates is of great interest for numerous applications in the fields of biosensors and biomaterials. We report on the preparation and the morphological characterization of a tethering system for lipidic bilayers, which is based on cholesteryl derivatives deposited on hydrophilic surfaces by self-assembling and microcontact printing techniques. The investigation of the structural properties of the realized films by atomic, lateral, and surface potential microscopy allowed us to assess the high quality of the realized cholesteryl layers.

Formation and characterization of glutamate dehydrogenase monolayers on silicon supports

In this paper we have tested two different procedures (the "three-step" and the "four-step" procedures) for the covalent immobilization of glutamate dehydrogenase (GDH) onto silicon supports. Atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FT-IR), fluorescence spectroscopy and an enzymatic assay were used to probe the structure and activity of the immobilized enzyme. Our results demonstrate that coupling through the "three-step" procedure does not significantly affect either the fold pattern or the activity of the enzyme, suggesting that this method could be ideally suited to the development of high quality monolayers for use in enzyme-based planar biosensors.