Canakinumab as Adjuvant Therapy in Patients With Completely Resected Non-Small-Cell Lung Cancer: Results From the CANOPY-A Double-Blind, Randomized Clinical Trial

PURPOSE

Effective treatments for resectable non-small-cell lung cancer (NSCLC) are limited and relapse rates are high. The interleukin (IL)-1β pathway has been linked with tumor development and progression, including in the Canakinumab Anti-Inflammatory Thrombosis Outcomes cardiovascular study in which IL-1β pathway inhibition with canakinumab reduced lung cancer incidence and mortality in an exploratory analysis.

METHODS

CANOPY-A (ClinicalTrials.gov identifier: NCT03447769) is a phase III, randomized, double-blind, multicenter study of canakinumab versus placebo for adult patients with stage II-IIIA or IIIB (T >5 cm, N2-positives II-IIIB; American Joint Committee on Cancer/Union for International Cancer Control version 8), completely resected NSCLC who had received adjuvant cisplatin-based chemotherapy. The primary end point was disease-free survival (DFS) and the key secondary end point was overall survival (OS).

RESULTS

In total, 1,382 patients were randomized to 200 mg canakinumab (n = 693) or placebo (n = 689) once every 3 weeks for 18 cycles. Grade ≥3 adverse events (AEs) were reported in 20.8% and 19.6% of patients receiving canakinumab and placebo, respectively; AEs led to discontinuation in 4.3% and 4.1% of patients in these groups, respectively. This study did not meet its primary end point. Median DFS was 35.0 months (canakinumab arm) and 29.7 months (placebo arm; hazard ratio, 0.94; 95% CI, 0.78 to 1.14; one-sided P = .258). DFS subgroup analyses did not show any meaningful differences between arms. As expected, because of canakinumab-driven IL-1β pathway inhibition, C-reactive protein and IL-6 levels decreased in the canakinumab arm versus placebo arm, but had no correlation with differential clinical outcomes. OS was not formally tested as DFS was not statistically significant.

CONCLUSION

CANOPY-A did not show a DFS benefit of adding canakinumab after surgery and adjuvant cisplatin-based chemotherapy in patients with resected, stage II-III NSCLC. No new safety signals were identified with canakinumab.

Abstract LBA039: Canakinumab as Adjuvant Therapy in Patients With Completely Resected Non-Small Cell Lung Cancer: CANOPY-A Trial

Background: In the CANTOS study, canakinumab (selective interleukin 1β inhibitor) treatment was associated with reduced incidence and mortality from non-small cell lung cancer (NSCLC) in stable post–myocardial infarction patients with elevated high-sensitivity C-reactive protein (hs-CRP) levels. The CANOPY-A study was designed to investigate the therapeutic role of canakinumab in NSCLC. Methods: The CANOPY-A study (NCT03447769) is evaluating the efficacy and safety of canakinumab as adjuvant therapy in adult patients with completely resected NSCLC. Patients with American Joint Committee on Cancer/Union for International Cancer Control version 8 stage IIA-IIIA and IIIB (T >5 cm, N2), any histology, completely resected (R0) NSCLC and completion of adjuvant cisplatin-based chemotherapy (≥2 cycles) and radiotherapy (if applicable) are eligible. Patients must not have had prior neoadjuvant chemotherapy or radiotherapy. Patients (~1500) are randomized 1:1 to receive canakinumab (200 mg) or placebo subcutaneously every 3 weeks for 18 cycles or until disease recurrence as determined by investigator, unacceptable toxicity, or treatment discontinuation at the discretion of the investigator. The primary objective is to compare disease-free survival (DFS) in the canakinumab versus placebo arm per local investigator assessment. Secondary objectives are overall survival (OS), lung cancer–specific survival, safety, pharmacokinetics, immunogenicity, and patient-reported outcomes. Adult patients with stage IIA-IIIA and IIIB (T>5 cm, N2 disease only) NSCLC who are candidates for complete resection surgery (and therefore prospective candidates for the main study) will be asked to participate in a biomarker substudy to understand how resection may impact biomarkers involved in the interleukin 1β inflammatory pathway and mutations present in blood. In the substudy, the levels of hs-CRP, other cytokines, and additional biomarkers in blood will be assessed before and after surgery (endpoint: summary statistics of hs-CRP and other pharmacodynamic biomarkers). For patients who will enroll in the main study, possible associations between pre- and post-surgery biomarker levels with canakinumab efficacy will be assessed (endpoint: DFS and OS by hs-CRP and other pharmacodynamic biomarkers). The CANOPY-A study is currently enrolling. As of August 6, 2021, there are 399 study locations.

Citation Format: Edward B. Garon, Andrea Ardizzoni, Fabrice Barlesi, Byoung Chul Cho, Pedro De Marchi, Yasushi Goto, Dariusz Kowalski, Shun Lu, David R. Spigel, Michael Thomas, James Chih-Hsin Yang, Sabine Turri, Wen Zhou, Teri Kreisl, Luis Paz-Ares. Canakinumab as Adjuvant Therapy in Patients With Completely Resected Non-Small Cell Lung Cancer: CANOPY-A Trial [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr LBA039.

Historical Benchmarks for Quality Tolerance Limits Parameters in Clinical Trials

Background

In 2016, the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use updated its efficacy guideline for good clinical practice and introduced quality tolerance limits (QTLs) as a quality control in clinical trials. Previously, TransCelerate proposed a framework for QTL implementation and parameters. Historical data can be important in helping to determine QTL thresholds in new clinical trials.

Methods

This article presents results of historical data analyses for the previously proposed parameters based on data from 294 clinical trials from seven TransCelerate member companies. The differences across therapeutic areas were assessed by comparing Alzheimer’s disease (AD) and oncology trials using a separate dataset provided by Medidata.

Results

TransCelerate member companies provided historical data on 11 QTL parameters with data sufficient for analysis for parameters. The distribution of values was similar for most parameters with a relatively small number of outlying trials with high parameter values. Medidata provided values for three parameters in a total of 45 AD and oncology trials with no obvious differences between the therapeutic areas.

Conclusion

Historical parameter values can provide helpful benchmark information for quality control activities in future trials.

Abstract CT255: Canakinumab as adjuvant therapy in patients with completely resected non-small cell lung cancer: CANOPY-A trial

Background: In the CANTOS study, canakinumab (selective interleukin 1β inhibitor) treatment was associated with reduced incidence and mortality from non-small cell lung cancer (NSCLC) in stable post-myocardial infarction patients with elevated high-sensitivity C-reactive protein (hsCRP) levels. The CANOPY-A study was designed to investigate the therapeutic role of canakinumab in NSCLC. Methods: The CANOPY-A study (NCT03447769) is evaluating the efficacy and safety of canakinumab as adjuvant therapy in adult patients with completely resected NSCLC. Patients with American Joint Committee on Cancer/Union for International Cancer Control version 8 stage IIA-IIIA and IIIB (T >5 cm, N2), any histology, completely resected (R0) NSCLC and completion of adjuvant cisplatin-based chemotherapy (≥2 cycles) and radiotherapy (if applicable) are eligible. Patients must not have had prior neoadjuvant chemotherapy or radiotherapy. Patients (~1500) are randomized 1:1 to receive canakinumab (200 mg) or placebo subcutaneously every 3 weeks for 18 cycles or until disease recurrence as determined by investigator, unacceptable toxicity, or treatment discontinuation at the discretion of the investigator. The primary objective is disease-free survival (DFS) per local investigator assessment. Secondary objectives are overall survival (OS), lung cancer-specific survival, safety, pharmacokinetics, immunogenicity, and patient-reported outcomes. Adult patients with stage IIA-IIIA and IIIB (T>5 cm, N2 disease only) NSCLC who are candidates for complete resection surgery (and therefore prospective candidates for the main study) will be asked to participate in a biomarker substudy to understand how resection may impact biomarkers involved in the interleukin 1β inflammatory pathway and mutations present in blood. In the substudy, the levels of hs-CRP, other cytokines, and additional biomarkers in blood will be assessed before and after surgery (endpoint: summary statistics of hs-CRP and other pharmacodynamic biomarkers). For patients who will enroll in the main study, possible associations between pre- and postsurgery biomarker levels with canakinumab efficacy will be assessed (endpoint: DFS and OS by hs-CRP and other pharmacodynamic biomarkers). The CANOPY-A study is currently enrolling. As of October 19, 2020, there are 356 study locations.

Citation Format: Alexander Spira, Andrea Ardizzoni, Fabrice Barlesi, Byoung Chul Cho, Pedro De Marchi, Yasushi Goto, Dariusz Kowalski, Shun Lu, Luis Paz-Ares, David R. Spigel, Michael Thomas, Sabine Turri, Vanessa Rodrik-Outmezguine, Wen Zhou, Terri Kreisl, James Chih-Hsin Yang, Edward B. Garon. Canakinumab as adjuvant therapy in patients with completely resected non-small cell lung cancer: CANOPY-A trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT255.

Abstract P5-21-06: Alpelisib plus letrozole in estrogen receptor-Positive (ER+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (aBC): Safety and preliminary efficacy analysis from a phase 1b trial

Background

Endocrine therapy is the standard first-line treatment for postmenopausal patients (pts) with ER+, HER2– aBC. However, resistance eventually develops, often through dysregulation of PI3K/AKT/mTOR pathway, specifically mutations in PIK3CA, the gene encoding the p110α subunit of PI3K. The oral, selective PI3K inhibitor alpelisib and letrozole synergistically inhibits tumor growth in preclinical models of ER+ breast cancer. Alpelisib plus letrozole in pts with ER+ aBC is being investigated in arm 2 of a multi-arm, phase 1b study (NCT01872260).

Methods

Postmenopausal women with ER+, HER2− aBC received alpelisib (300 mg QD; continuous, 28 days cycle) plus letrozole (2.5 mg QD; continuous). Primary endpoints were to confirm MTD/RP2D of alpelisib plus letrozole in the escalation phase and to further characterize safety and tolerability in the expansion phase. Secondary and exploratory endpoints included efficacy, pharmacokinetics, and biomarkers.

Results

As of August 19, 2016, 56 pts had received alpelisib plus letrozole: 19 pts were enrolled in the escalation phase (designated here as previously treated group), of which, 95% of pts were previously treated for aBC and 37 pts were enrolled in the expansion phase (designated here as first-line group), of which, 81% of pts were treatment-naïve for aBC. 16 previously treated pts and 11 first-line pts (48% of all pts) have discontinued treatment. Most common reasons for treatment discontinuation in the full population were disease progression (23.2%) and adverse events (AEs) (8.9%). Median duration of exposure of combination (alpelisib plus letrozole) was 23 weeks and 12.7 weeks in previously treated and first-line groups, respectively. Most frequently reported any grade treatment-related AEs (≥20% incidence) in all pts were hyperglycemia (48.2%), diarrhea (48.2%), nausea (33.9%), and decreased appetite (28.6%). Most common, grade 3 or 4 AEs (≥3% incidence) suspected to be treatment-related in all pts included hyperglycemia (17.9%), rash (5.4%), and diarrhea (3.6%). Median progression-free survival was 5.7 months in the previously treated group and was not reached in the first-line group. A summary of best overall response, overall response rate and clinical benefit rate in evaluable pts is shown in the table.

 Alpelisib+Letrozole (Previously Treated group) [N=19]Alpelisib+Letrozole (First-line group) [N=27]All subjects (N=46)Best overall response, n (%)Confirmed CR000Confirmed PR04 (14.8)4 (8.7)NCRNPD6 (31.6)9 (33.3)15 (32.6)SD8 (42.1)9 (33.3)17 (37.0)PD2 (10.5)1 (3.7)3 (6.5)Unknown3 (15.8)3 (11.1)6 (13.0)ORR (CR+PR), % (95% CI)0 (0.0-17.6)14.8 (4.2-33.7)8.7 (2.4-20.8)CBR [CR+PR+(SD/NCRNPD)], % (95% CI)36.8 (16.3-61.6)70.8 (48.9-87.4)55.8 (39.90-70.9)CBR; clinical benefit rate; CI, confidence interval; CR, complete response; NCRNPD; Non-CR/Non-PD; ORR; overall response rate; PD; progressive disease; SD, stable disease.

Conclusions

Based on these preliminary data, the combination of alpelisib plus letrozole had manageable safety profile in pts with ER+, HER2– aBC and demonstrated encouraging clinical activity, particularly in the first-line patient population.

Citation Format: Juric D, Gonçalves A, Hamilton E, Boni V, Mayer IA, Turri S, Wang Y, Vogl FD, Sellami D, Campone M. Alpelisib plus letrozole in estrogen receptor-Positive (ER+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (aBC): Safety and preliminary efficacy analysis from a phase 1b trial [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 P5-21-06.

Neoadjuvant buparlisib plus trastuzumab and paclitaxel for women with HER2+ primary breast cancer: A randomised, double-blind, placebo-controlled phase II trial (NeoPHOEBE)

AIM

The Neoadjuvant PI3K inhibition in HER2 OverExpressing Breast cancEr (NeoPHOEBE) trial evaluated the efficacy and safety of buparlisib, a pan-phosphatidylinositol 3-kinase (PI3K) inhibitor, plus trastuzumab and paclitaxel as neoadjuvant treatment for human epidermal growth factor receptor-2 positive (HER2+) breast cancer.

METHODS

NeoPHOEBE was a neoadjuvant, phase II, randomised, double-blind study. Women with HER2+ breast cancer were randomised within two independent cohorts by PIK3CA mutation status and, in each cohort stratified by oestrogen receptor (ER) status to receive buparlisib or placebo plus trastuzumab (first 6 weeks) followed by buparlisib or placebo with trastuzumab and paclitaxel. Primary end-point was pathological complete response (pCR) rate; key secondary end-point was objective response rate (ORR) at 6 weeks. Exploratory end-points were evaluation of Ki67 levels and change in tumour infiltrating lymphocytes (TILs) in intermediate biopsies at day 15.

RESULTS

Recruitment was suspended mainly due to liver toxicity after enrolment of 50 of the planned 256 patients. In each arm (buparlisib n = 25; placebo n = 25) 21 patients (84%) had wild type PIK3CA and 4 patients (16%) had mutant PIK3CA. Overall, pCR rate was similar between buparlisib and placebo arms (32.0% versus 40%; one-sided P = 0.811). A trend towards higher ORR (68.8% versus 33.3%; P = 0.053) and a significant decrease in Ki67 (75% versus 26.7%; P = 0.021) was observed in buparlisib versus placebo arm in the ER+ subgroup (Pinteraction = 0.03).

CONCLUSIONS

Addition of the pan-PI3K inhibitor buparlisib to taxane-trastuzumab-based therapy in HER2+ early breast cancer was not feasible. However, the higher ORR and Ki67 reduction in the ER+, HER2+ subgroup indicates a potential role for PI3K-targeted therapy in this setting and may warrant further investigation with better-tolerated second-generation PI3K inhibitors.

TRIAL REGISTRATION IDENTIFIER

NCT01816594.

Effect of 3D-Printed Microvascular Network Design on the Self-Healing Behavior of Cross-Linked Polymers

This article describes the manufacturing procedure and the characterization of self-healing polymers based on embedded microvascular networks. The samples were realized by resin casting into water-soluble PVA molds, fabricated via 3D printing. This technology allowed us to exploit the 3D printers' ability to produce complex structures with high resolution for the creation of independent microchannels networks. The two reacting components of a two-part resin could be stored separately within the microstructure. The materials' self-healing ability resulted from their reaction when severe damage caused the healing liquids to leak out, wetting the sample cross section and diffusing one into the other. The mechanical properties of healed samples were investigated by means of uniaxial tensile tests and compared to those of undamaged samples. The effect of microchannel density and different network designs on self-healing efficiency was determined. The different microstructures used were characterized using computerized X-ray microtomography. The versatility of the fabrication technique presented in this work allows conversion of any water-resistant resin into a fully functional self-healing polymeric composite.

Phase Ib dose-finding study of abiraterone acetate plus buparlisib (BKM120) or dactolisib (BEZ235) in patients with castration-resistant prostate cancer

BACKGROUND

The phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signalling axis and androgen receptor (AR) pathways exhibit reciprocal feedback regulation in phosphatase and tensin homologue (PTEN)-deficient metastatic castration-resistant prostate cancer (CRPC) in preclinical models. This phase Ib study evaluated the pan-PI3K inhibitor buparlisib (BKM120) and the dual pan-PI3K/ mammalian target of rapamycin (mTOR) inhibitor dactolisib (BEZ235) in combination with abiraterone acetate (AA) in patients with CRPC.

MATERIALS AND METHODS

Patients with CRPC who had progressed on AA therapy received escalating doses of either buparlisib or dactolisib, along with fixed doses of AA (1000 mg once daily (qd)) and prednisone (5 mg twice daily (bid)). The primary objective was to define the maximum tolerated dose (MTD) and/or the recommended dose for expansion (RDE) of either buparlisib or dactolisib in combination with AA. Secondary objectives included safety, antitumour activity (Prostate Cancer Working Group 2 (PCWG2) criteria; 30% of prostate-specific antigen (PSA) decline at ≥week 12) and pharmacokinetic (PK) profile.

RESULTS

In buparlisib + AA arm, 25 patients received buparlisib + AA (median age, 67 years; Eastern Cooperative Oncology Group performance status (ECOG PS) of 0/1/2 for 7/17/1 patients, respectively). At 100 mg qd; two patients experienced dose-limiting toxicities (DLTs) (grade 3 hyperglycaemia; grade 2 asthenia), and this was the maximum buparlisib dose explored. Buparlisib + AA showed a 26% lower median area under the curve from time zero to 24°h (AUC_0-24) and 48% lower median maximum serum concentration (Cmax) versus the single-agent buparlisib assessed in first-in-human study. No objective response and few PSA decreases were reported. In dactolisib + AA arm, 18 patients (median age, 71 years; ECOG PS of 0/1 for 6/12 patients, respectively) received dactolisib + AA at the first dose level (200 mg bid). Five patients had 9 DLTs (grades 2&3 stomatitis; grade 3 hyperglycaemia; grades 2& 3 diarrhoea; grades 1& 2 pyrexia, grade 2 vomiting, and grade 2 chills).

CONCLUSIONS

Based on the assessment of available pharmacokinetics, safety, and efficacy data, no further study is planned for either buparlisib or dactolisib in combination with AA in CRPC.

A Phase II Study of BEZ235 in Patients with Everolimus-resistant, Advanced Pancreatic Neuroendocrine Tumours

BACKGROUND

This was a two-stage, phase II trial of the dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor BEZ235 in patients with everolimus-resistant pancreatic neuroendocrine tumours (pNETs) (NCT01658436).

PATIENTS AND METHODS

In stage 1, 11 patients received 400 mg BEZ235 orally twice daily (bid). Due to tolerability concerns, a further 20 patients received BEZ235 300 mg bid. Stage 2 would be triggered by a 16-week progression-free survival (PFS) rate of ≥60% in stage 1.

RESULTS

As of 30 June, 2014, 29/31 patients had discontinued treatment. Treatment-related grade 3/4 adverse events were reported in eight (72.7%) patients at 400 mg and eight (40.0%) patients at 300 mg, including hyperglycaemia, diarrhoea, nausea, and vomiting. The estimated 16-week PFS rate was 51.6% (90% confidence interval=35.7-67.3%).

CONCLUSION

BEZ235 was poorly tolerated by patients with everolimus-resistant pNETs at 400 and 300 mg bid doses. Although evidence of disease stability was observed, the study did not proceed to stage 2.

Rheological and mechanical behavior of polyacrylamide hydrogels chemically crosslinked with allyl agarose for two-dimensional gel electrophoresis

Two-dimensional (2-D) gel electrophoresis currently represents one of the most standard techniques for protein separation. In addition to the most commonly employed polyacrylamide crosslinked hydrogels, acrylamide-agarose copolymers have been proposed as promising systems for separation matrices in 2-D electrophoresis, because of the good resolution of both high and low molecular mass proteins made possible by careful control and optimization of the hydrogel pore structure. As a matter of fact, a thorough understanding of the nature of the hydrogel pore structure as well as of the parameters by which it is influenced is crucial for the design of hydrogel systems with optimal sieving properties. In this work, a series of acrylamide-based hydrogels covalently crosslinked with different concentrations of allyl agarose (0.2-1%) is prepared and characterized by creep-recovery measurements, dynamic rheology and tensile tests, in the attempt to gain a clearer understanding of structure-property relationships in crosslinked polyacrylamide-based hydrogels. The rheological and mechanical properties of crosslinked acrylamide-agarose hydrogels are found to be greatly affected by crosslinker concentration. Dynamic rheological tests show that hydrogels with a percentage of allyl agarose between 0.2% and 0.6% have a low density of elastically effective crosslinks, explaining the good separation of high molecular mass proteins in 2-D gel electrophoresis. Over the same range of crosslinker concentration, creep-recovery measurements reveal the presence of non-permanent crosslinks in the hydrogel network that justifies the good resolution of low molecular mass proteins as well. In tensile tests, the hydrogel crosslinked with 0.4% of allyl agarose exhibits the best results in terms of mechanical strength and toughness. Our results show how the control of the viscoelastic and the mechanical properties of these materials allow the design of mechanically stable hydrogels with improved sieving ability in protein electrophoresis over a wide range of molecular masses.

Failure of silicone gel breast implants: is the mechanical weakening due to shell swelling a significant cause of prostheses rupture?

Silicone gel-filled breast implants nowadays are commonly used in breast surgery. Despite the improvements carried out during the years in the device design and manufacturing technologies, the long-term reliability of such prostheses is still doubted and the phenomena involved in the prostheses failure not yet clearly defined. This study investigates rupture causes by analysing the mechanical properties of failed and intact implants in the recent generation of silicon gel breast implants. The main scope is to assess whether mechanical weakness of the shells should be considered as a major cause of breast implant rupture or, on the contrary, the prosthesis shell damage is likely due to other random factors. Some tests were performed on the shells of a wide number of explanted prostheses, to evaluate the mechanical properties as a function of prostheses status at explantation (intact/ruptured) and variable degree of swelling. A weakening of the shell mechanical properties, so as a significant difference in the ultimate strength and stiffness of intact versus ruptured prostheses, was found. This attenuation of the properties may be justified as a consequence of the shell swelling phenomenon during implantation and has to be considered as a significant mechanism for silicone gel breast implant failure.

Design, fabrication, and characterization of a composite scaffold for bone tissue engineering

Poly(lactide-co-glycolide) (PLGA) scaffolds have been successfully used in bone tissue engineering, with or without hydroxyapatite (HA) and with a macroporosity given either by simple PLGA sphere packaging and/or by leaching out NaCl. The objective of this work was the optimization of the design parameters for bone tissue engineering scaffolds made by sintering microspheres of PLGA, HA nanocrystals for matrix reinforcement and osteoconduction, and salt crystals for macroporosity and control of matrix pore size. Microsphere fabrication by a single-emulsion and solvent evaporation technique was first optimized to obtain a high yield of PLGA microspheres with a diameter between 80 and 300 microm. The influence of the sintering process and matrix composition on the scaffold structure was then evaluated morphologically and mechanically. Three scaffold types were tested for biocompatibility by culturing with human fibroblasts for up to 14 days. The most important parameters to obtain microspheres with the selected diameter range were the viscosity ratio of the dispersed phase to the continuous phase and the relative volume fraction of the 2 phases. The Young's modulus and the ultimate strength of the sintered matrices ranged between 168-265 MPa and 6-17 MPa, respectively, within the range for trabecular bone. Biocompatibility was demonstrated by fibroblast adhesion, proliferation, and spreading throughout the matrix. This work builds upon previous work of the PLGA/HA sintering technique to give design criteria for fabricating a bone tissue engineered matrix with optimized morphological, functional, and biological properties to fit the requirements of bone replacements.

Structure, wettability and thermal degradation of new fluoro-oligomer modified nanoclays

Quaternary ammonium salts based on monofunctionalized Perfluoropolyether (PFPE) oligomers were synthesized and used for the cation exchange process of sodium Montmorillonite nanoclays. The new fluoromodified nanoclays were characterized through X-rays diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), termogravimetric analysis (TGA), differential scanning calorimetry (DSC), electronic microscopy (SEM-EDS), and contact angle measurements (CA). In particular XRD showed rather complex patterns (presence of higher order reflections) which allowed the calculation of basal spacings, regularly increasing with the molecular weight of the fluorinated macrocation. Both IR and SEM confirmed the presence of fluorinated segments at clays interface, while TGA showed a limited thermal stability with an onset of degradation temperature which seems not dependent on the molecular weight of the macrocation. CA measurements showed a peculiar behaviour, with evident dynamic hysteresis phenomena and surface tension components quite different from those of commercially available, organomodified clays.

Novel blocked functionality copolymers as surface coatings in DNA microarray technology

New copolymers made of 2-(dimethyl amino) ethyl methacrylate (DMAEM) and isocyanate ethyl methacrylate blocked with methyl ethyl ketoxime (IEMB) was synthesized in various composition ratios in order to obtain water reducible copolymers after acidification. They were characterized by infrared spectroscopy, chemical titration for the determination of amine equivalent weight, and by differential scanning calorimetry (DSC). Calorimetric analysis showed the presence of a former broad endothermal peak followed by a latter, stronger exothermal one, which can be respectively attributed to the deblocking of isocyanate groups and to their subsequent reactions. Some copolymer compositions were dip coated onto microscope glass slides and surfaces were characterized by static and dynamic contact angles, revealing a clear effect of the salifying agent and a likely surface rearrangement of polar groups while in contact with water. Finally, oligonucleotides surface immobilization and molecular recognition capability of the coated glass slides were positively assessed by hybridization tests with fluorescently labelled complementary probes.

Self-Assembly of Methacrylic Nanostructured Copolymers Containing Polyhedral Oligomeric Silsesquioxanes

Two hybrid copolymer series obtained by free-radical copolymerization of methacrylcyclohexyl Polyhedral oligomeric silsesquioxane (POSS) with butyl methacrylate or 2-ethylhexylmethacrylate were characterized by 1H-NMR spectroscopy, gel permeation chromatography (GPC), X-rays Diffraction (XRD), differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). Reactivity ratios were calculated by low yield composition data suggesting the formation of random copolymers with low probability of poly-POSS sequences. XRD studies showed the crystallization behaviour of the inorganic phase independently on the POSS content; however sample processing by solvent casting effectively hindered the copolymer self-assembling ability. DSC suggests the formation of polyphasic structures with Tg increasing with POSS content, and with endothermal peaks occurring at higher temperature. Finally TGA shows an improved thermal stability of hybrid copolymers with char yield correlated to the level of inorganic phase.

Fourier transform infrared studies on deblocking and crosslinking mechanisms of some fluorine containing monocomponent polyurethanes

The thermal reactivity of a set of different blocked perfluoropolyether (PFPE) containing polyisocyanates and one monocomponent polyurethane containing a PFPE diol was investigated by Fourier transform infrared (FT-IR) spectroscopy. With the former series of products the deblocking kinetics at 90 degrees C and 120 degrees C were investigated with time-dependent spectral data, showing the highest thermal deblocking activity for 3,5 dimethylpyrazole blocking agent. The crosslinking reaction of the PFPE diol with ketoxime blocked isocyanurate at 150 degrees C was monitored by infrared (IR) spectroscopy and two-dimensional (2D) correlation analysis; the results suggested a prevailing direct condensation mechanism and the formation of urea byproducts in the later stages of reaction. Both synchronous and asynchronous spectra were considered and discussed, pointing out the time relation of the chemical functions during the crosslinking experiment.