Fossil fuels’ pollution and their non-renewability have motivated the search for alternative fuels. Some common example of seed oils are sunflower oil, date seed oil, soy bean oil. For instance, soy methyl and soy-based biodiesel are the main biodiesel. Biodiesel is a clean diesel fuel that can be produced through transesterification reaction. Recycled cooking oil, on the other hand, is one of the inexpensive, easily available sources for producing biodiesel. This article is aimed at production of biodiesel via trans-esterification method, Nano CaO synthesis using sol-gel method, and Nano MgO synthesis using sol-gel self-combustion. Two catalysts’ combination affecting the reaction’s efficacy was also discussed. Optimum conditions for the reaction in the presence of Nano CaO are 1.5 % weight fracture, 1:7 alcohol to oil proportion and 6 h in which biodiesel and glycerin (the byproduct) are produced. Moreover, the optimum conditions for this reaction in the presence of Nano CaO and Nano MgO mixture are 3 % weight fracture (0.7 g of Nano CaO and 0.5 g of Nano MgO), 1:7 alcohols to oil proportion and 6 h. Nano MgO is not capable of catalyzing the transesterification by itself, because it has a much weaker basic affinity but when used with Nano CaO due to its surface structure, the basic properties increase and it becomes a proper base for the catalyst so that CaO contact surface increases and transesterification reaction yield significantly increases as well. This study investigates the repeatability of transesterification reaction in the presence of these Nano catalysts as well.
Purpose: The aim of this study was to investigate transmission of topical silicate nanoparticles (SiNPs) through the corneal stroma, anterior chamber, and vitreous fluids by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and inductively coupled plasma atomic emission spectrometry (ICP-AES), respectively. Methods: SiNPs with a mean diameter of 40.6 ± 5.6 nm determined by dynamic light scattering were used in this study. The permeability of SiNPs was examined across isolated corneal buttons over a 30-minute period. To visualize the transport and diffusion of nanoparticles through the corneal tissue, SiNPs were applied over the corneal surface and evaluated at 5 and 30 minutes after SiNPs loading for SEM and 15 minutes for TEM. Sections of 10-μm thickness were cut and visualized using SEM. TEM study was performed on 70- to 90-nm-thick sections. ICP-AES was used to determine the concentration of SiNPs. Results: The determined range of synthesized SiNPs by dynamic light scattering was 40 nm (41.9 ± 5.6 nm). Transmission of SiNPs through the corneal stroma was shown successfully with electron microscopic (SEM and TEM) images. The ICP-AES results revealed SiNPs in the anterior chamber and vitreous fluid. Conclusions: Topical administration of SiNPs, as a noninvasive, and available modality with acceptable penetration through the corneal stroma and deep into the intraocular fluids including the anterior chamber and vitreous cavity, may be considered as a suitable alternative to invasive intravitreal injection of other expensive antineovascularization agents.
Background: Angiogenesis-related corneal blindness includes the spectrum of corneal diseases that are caused by pathological angiogenesis, leading to untoward visual impairment. The purpose of this study was to investigate the antineovascularization effect of topical silica nanoparticles (SiNPs) in inhibiting chemical-burn-induced corneal neovascularization. Materials and Methods: A total number of 20 corneas of 10 Wistar Albino rats were included in this study. Silver nitrate cauterization was pressed to the central cornea for 5 s to induce corneal neovascularization. They were randomly allocated to case and control groups (ten eyes in each group). SiNPs were synthesized by the reverse microemulsion method. SiNPs drop 1 mg/ml was started in ten eyes and artificial tear drop was started in the control group (ten eyes) immediately after chemical cauterization. Video-based photography was performed before and after treatment. Corneal image analysis was performed on each cornea using an image analysis software program. All rats were euthanized and the eyes were sent for histopathologic examinations14 days after chemical cauterization. Results: Scanning electron microscopy (SEM) images showed spherical-shaped particles. The mean size and polydispersity index of prepared SiNPs were 30.1 ± 5.6 nm and 0.254 ± 0.11, respectively. Fourteen days after chemical cauterization, the mean vascularized corneal area was 21% of total corneal area in the case group and 85% in the control group (P < 0.05). The control group revealed more extensive intrastromal vascularization compared with the case group in histopathologic examinations (P < 0.05). Conclusions: SiNPs is an effective modality for inhibiting corneal neovascularization following chemical burn in an experimental model. Further investigations are suggested for evaluation of its safety and efficacy in human eyes.
Purpose. To assess the safety of biosimilar intravitreal aflibercept (CinnaGen Co., Iran) compared to the reference product (Eylea®; Bayer Schweiz AG, Zurich, Switzerland) in rabbit eyes through functional and histologic studies. Methods. Forty New Zealand albino rabbits were recruited to the study and were divided into four groups to be sacrificed at 48 hours, one, two, and four weeks after injections. In each group, five rabbits received 0.05 mL (2 mg) biosimilar aflibercept in the right eye and 0.05 mL saline in the left eye as the control, and in a similar manner, the remaining five rabbits received the reference drug in the right eye and saline in the left eye. All the rabbits underwent comprehensive ophthalmic examination and electroretinography (ERG) tests at baseline and also just before enucleation at the specific predefined time points. The enucleated eyes were prepared for retinal toxicity histological examination. Results. No retinal toxicity was observed based on histologic and ERG findings in all groups. Choroidal congestion was revealed after 1 week in an eye that was injected with biosimilar aflibercept, although the similar finding was detected in the contralateral eye which received saline. Also, one subject which received the reference drug showed chronic vitritis and lymphoplasmocytic reaction of the optic disc at week 4. The remaining subjects showed no histologic changes. Conclusion. The 2 mg intravitreal injection of biosimilar aflibercept (CinnaGen Co., Iran) was found to be nontoxic in rabbit eyes in the short-term period. Further studies are required to warrant the efficacy and safety profile of the drug in human subjects.