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Adjuncts in Vitreoretinal Surgery
Published in Pradeep Venkatesh, Handbook of Vitreoretinal Surgery, 2023
Vitreous substitutes may be classified based on the physical nature of the substance as well as the duration of stay within the eyeball. Based on the physical nature, they could be gases [e.g., air, sulphur hexafluoride, perfluoropropane] or liquids [e.g., silicone oil, perfluorocarbon liquids such as perfluorodecalin, perfluoro-n-octane-perfluoron, perfluorophenentherene, vitreon, and synthetic gels (still in experimental stages)]. Gaseous vitreous substitutes are self-absorbing over variable amounts of time. In contrast, liquid substitutes have to be surgically removed. Short-acting vitreous substitutes stay for a few days to about 10 days, while long-acting substitutes stay for several weeks. It is interesting to note that many of the vitreous substitutes were actually being used earlier, either in industry or for non-ocular medical purposes.
Order Martellivirales: Virgaviridae
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
To broaden further putative applications, He et al. (2009) investigated behavior of the TMV rods at liquid/liquid interfaces, namely the oil/water interface. Remarkably, TMV showed different orientations at the perfluorodecalin/water interface, depending on the initial TMV concentration in the aqueous phase. Thus, at low TMV concentration, the rods oriented parallel to the interface, mediating the interfacial interactions at the greatest extent per particle. At high TMV concentrations, the rods were oriented normal to the interface, mediating the interfacial interactions and also neutralizing interrod electrostatic repulsion.
Membrane removal in proliferative vitreoretinopathy
Published in A Peyman MD Gholam, A Meffert MD Stephen, D Conway MD FACS Mandi, Chiasson Trisha, Vitreoretinal Surgical Techniques, 2019
Michael S L.e.e, Gary W Abrams
The PFCL is removed during a fluid–air exchange. Before removing the PFCL, subretinal fluid anterior to the PFCL is aspirated through anterior retinal breaks with a soft-tipped needle. A wide-angle system or indirect ophthalmoscopy will provide adequate visualization for this procedure. After all the subretinal fluid has been removed, the PFCL is aspirated. If perfluoro-n -octane is used, it can be identified easily and removed. Minuscule amounts on the retinal surface will evaporate at body temperature. Perfluorodecalin and perfluoroperhydrophenanthrene do not evaporate, and are more difficult to identify. Therefore, a small aliquot of balanced saline is injected over the posterior pole to help detect any remaining PFCL, so that it can be removed.
Fluorinated vectors for gene delivery
Published in Expert Opinion on Drug Delivery, 2022
Yu Wan, Yuhan Yang, Mingyu Wu, Shun Feng
In addition to being used alone as a gene delivery vehicle, fluorinated PEI has also been reported to be combined with other materials to deliver genes. For example, it was added into perfluorodecalin emulsions as a surfactant to reduce PEI toxicity and increase siRNA [58] and DNA [59] transfection efficacy. The fluorinated PEI was doped into carbon dots for cell imaging and DNA delivery [60]. Moreover, a partially fluorinated PEI (1.8 kDa), named PF33, complexed with plasmid to form the inner core, then coated with active-targeting RGD-R8-PEG- hyaluronic acid shell, which was used to deliver the large-size CRISPR-Cas9 system (Cas9-hMTH1) [61], hTRAIL plasmid [62] and SP-TAT-Apoptin plasmid [63], which all showed high transfection efficiency. Similarly, a tumor selective response module consisting of hyaluronic acid, PEG, cell-penetrating peptide and matrix metalloproteinases-2 -cleavable peptide linker, was coated on the fluorinated PEI to improve the tumor targetability, which has also been used to improve CRISPR/Cas9 technology for effective immunotherapy [64]. Meanwhile, a fluorinated disulfide-conjugated PEI copolymer with biotin functional group was applied to load plasmid ZNF580 to form nanoparticle, then MMP-cleavable peptide and vascular endothelial cells-selective peptide were grafted on the surface of nanoparticle [65]. More recently, fluorinated PEI was utilized to condense the TREM2-encoding plasmid and then coated with human serum albumin to treat Alzheimer’s disease [66].
Clinical potential of pre-reperfusion hypothermia in ischemic injury
Published in Neurological Research, 2019
Yun Han, Gary B. Rajah, Mohammed Hussain, Xiaokun Geng
A rabbit model [21] also demonstrated that ultra-early hypothermic induction led to a dramatic improvement in cardiovascular outcomes post cardiac arrest. In this study, the animals were divided into three groups: the control group (normothermic conditions), saline group (cold blankets and infusion of 4°C cold saline for 30 min) and the total liquid ventilation group (10 ml/kg of perfluorodecalin for 20 min). The target temperature was set to 32°C. Animals in the saline group reached the target temperature within 30–45 min after the onset of cooling and had mildly reduced infarct volume. In contrast, animals in the total liquid ventilation group achieved target temperatures within 5–10 min and had not only significantly decreased infarct volume but also improved cardiac output survival. This study also reinforced the notion of rapid hypothermia induction in improving cardiac outcome after myocardial infarction.
The effect of the perfluorodecalin patch on particle emission and skin temperature during laser-induced tattoo removal
Published in Journal of Cosmetic and Laser Therapy, 2020
Wojciech Danysz, Birgit Becker, Marion Begnier, Gaëlle Clermont, Peter Kreymerman
The above limitations encouraged researchers to find alternative treatment measures. One of them was the use of perfluorodecalin (PFD) which dissolves gases, acting as an optically clearing agent. PFD is a stable, metabolically inert, nontoxic fluorocarbon liquid that reduces optical scattering and reflection in the skin and increases tissue transparency from the ultraviolet to the far-infrared. This speeds up the disappearance of skin whitening, allowing multiple passes during one session (5). However, since the PFD evaporates rapidly, the procedure is somewhat labor intensive as multiple applications of PFD are necessary during treatment (6,7). A further improvement was the use of a silicone patch applied on top of the PFD to prevent rapid evaporation, which still allows laser transmission through the patch. The PFD patch consists of a dual-layer medical-grade transparent silicone film. The bottom layer is tacky so it can be easily applied to the skin, and perforated so the optical clearing agent, PFD, can wick into it (7). This PFD and silicone patch decreases skin whitening during the laser treatment and allows multiple passes in one session to faciliate much faster tattoo removal (6,7,16–18). However, the effects of the PFD patch on skin thermal exposure or particle emission into the air have not yet been systemically studied. Thus, the aim of this investigation was to assess changes in laser-induced thermal exposure of the skin using thermistor probes along with infrared (IR) camera and assess the efficacy of the PFD patch as a “barrier to ejecta” (i.e. preventing the emission of particles into the air using condensation particle counter).