Search

PURPOSE To compare the sealability of femtosecond laser (FSL)-assisted corneal incisions (CIs) with that of triplanar manual (M)-CIs and to determine FSL wound parameters minimizing leakage. SETTING Private practice. DESIGN Phase IV, single-surgeon, retrospective cohort study. METHODS One eye per patient was included. Two groups defined by the main wound (FSL-CI or M-CI) were compared for leakage, inferred by placement of a suture at the end of surgery. Leakage in FSL-CIs was analyzed as a function of customizable wound parameters: anterior plane depth (APD), posterior plane depth (PPD), anterior side-cut angle (ASCA), and posterior side-cut angle (PSCA). The risk of leakage of FSL-CIs with optimal and nonoptimal parameters was further compared with that of M-CIs. RESULTS A total of 1100 eyes (757 [68.8%] FSL-CI; 343 [31.2%] M-CI) were included. Wound leakage occurred in 133 FSL-CI (17.6%) and 30 M-CI eyes (8.7%) (P < .001). FSL wound parameters associated with the lowest risk of leakage were 60% APD, 70% PPD, 120 degrees ASCA, and 70 degrees PSCA. FSL-CIs constructed with at least 3 optimal parameters (60% APD, 70% PPD, and 120 degrees ASCA) had a similar risk of leakage to M-CIs (odds ratio [OR], 1.1; 95% CI, 0.5-2.3). FSL-CIs with suboptimal parameters had twice the risk of leakage of M-CIs (OR, 2.0; 95% CI, 1.1-3.8). CONCLUSIONS Overall, FSL-CIs leaked more than M-CIs. However, FSL-CIs with optimized wound profiles had an equivalent risk of leakage to M-CIs. Wound parameter customization is an asset of FSL technology that allows optimization of FSL-CI sealability.

Colloidal stability of nanoparticles in biological media is an important consideration when trying to ensure reliable data interpretation of in vitro and in vivo systems. We have developed a detailed colloidal stability library of newly synthesized gold, silver and gold-core silver-shell plasmonic nanoparticles, stabilized with aspartame, glucosamine and sucralose, in various biologically relevant buffers and bacterial and mammalian cell culture media. The stabilizer selection reflects the preference for molecules that are non-toxic, inexpensive, readily available, water soluble and easy-to-replace if that is the end-user preference. An on-line resource provides detailed stability information on each of the 81 systems examined. To illustrate how to utilize this stability library, we conducted bacterial toxicity and biocompatibility experiments through the use of one specific set of nanomaterials in the presence and absence of plasmonic irradiation.

Comparable intracellular concentrations (≈30pmol/10(6) cells) of bovine serum albumin-ZnPc (BSA) adduct outperformed dipalmitoyl-phosphatidyl-choline (DPPC) liposomes containing ZnPc at photodynamic-killing of human cervical cancer cells (HeLa) after only 15min of irradiation using red light (λ>620nm, 30W/cm(2)). This result could not be simply explained in terms of dye aggregation within the carrier, since in the liposomes the dye was considerably less aggregated than in bovine serum albumin, formulation that was capable to induce cell apoptosis upon red light exposure. Thus, using specific organelle staining, our cumulative data points towards intrinsic differences in intra-cellular localization depending on the cargo vehicle used, being ZnPc:BSA preferentially located in the near vicinity of the nucleus and in the Golgi structures, while the liposomal formulation ZnPc:DPPC was preferentially located in cellular membrane and cytoplasm. In addition to those differences, using real-time advanced fluorescence lifetime imaging of HeLa cells loaded with the photosensitizer contained in the different vehicles, we have found that only for the ZnPc:BSA formulation, there was no significant changes in the fluorescence lifetime of the photosensitizer inside the cells. This contrasts with the in situ≈two-fold reduction of the fluorescence lifetime measured for the liposomal ZnPc formulation. Those observations point towards the superiority of the protein to preserve dye aggregation, and its photochemical activity, post-cell uptake, demonstrating the pivotal role of the delivery vehicle at determining the ultimate fate of a photosensitizer.

Plasmon excitation of spherical gold nanoparticles carrying a fluorescent labeled 30 bp dsDNA cargo, with one chain covalently attached through two S–Au bonds to the surface, results in release of the complementary strand as ssDNA that can be examined in situ using high-resolution fluorescence microscopy. The release is dependent on the total energy delivered, but not the rate of delivery, an important property for plasmonic applications in medicine, sensors, and plasmon-induced PCR. Fil: Simoncelli, Sabrina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Bionanociencias "Elizabeth Jares Erijman"; Argentina. University of Ottawa; Canadá Fil: Alwis Weerasekera, Hasitha de. University of Ottawa; Canadá Fil: Fasciani, Chiara. University of Ottawa; Canadá Fil: Boddy, Christopher N.. University of Ottawa; Canadá Fil: Aramendia, Pedro Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Bionanociencias "Elizabeth Jares Erijman"; Argentina Fil: Alarcon, Emilio I.. University of Ottawa; Canadá Fil: Scaiano, Juan Cesar. University of Ottawa; Canadá

This chapter reviews the state of the art applications of silver nanoparticles in the biomedical sciences and health care, and aims to provide the reader with a general, but concise picture of the basic concepts that need to be considered when using silver nanoparticles (AgNP) in biological systems. We begin with a review of basic concepts on nanomaterials for biomedical applications. In the second part, we discuss a long-standing controversy regarding the risks versus benefits for the use of AgNP in the biomedical sciences. In the last section of this chapter, we present a discussion of future challenges regarding the use of AgNP in medicine.

Capping silver nanoparticles with LL37 peptide eradicates the antiproliferative effect of silver on primary skin cells, but retains the bactericidal properties of silver nanoparticles with activities comparable to silver nitrate or silver sulfadiazine. In addition, LL37 capped silver nanoparticles have anti-biofilm formation activity. Fil: Vignoni, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de la Plata; Argentina Fil: de Alwis Weerasekera, Hasitha. University Of Ottawa. Department of Chemistry and Centre for Catalysis Research and Innovation; Canadá Fil: Simpson, Madeline J.. University Of Ottawa. Department of Chemistry and Centre for Catalysis Research and Innovation; Canadá Fil: Phopase, Jaywant. Linking University. Integrative Regenerative Medicine Centre; Suecia Fil: Mah, Thien Fah . University of Ottawa.Faculty of Medicine; Canadá Fil: Griffith, May. Linköping University; Suecia Fil: Alarcon, Emilio I.. University Of Ottawa. Department of Chemistry and Centre for Catalysis Research and Innovation; Canadá Fil: Scaiano, Juan C.. University Of Ottawa. Department of Chemistry and Centre for Catalysis Research and Innovation; Canadá