SARS-CoV-2 Virus-like Particles with Plasmonic Au Cores and S1-Spike Protein Coronas

The COVID-19 pandemic has stimulated the scientific world to intensify virus-related studies aimed at the development of quick and safe ways of detecting viruses in the human body, studying the virus-antibody and virus-cell interactions, and designing nanocarriers for targeted antiviral therapies. However, research on dangerous viruses can only be performed in certified laboratories that follow strict safety procedures. Thus, developing deactivated virus constructs or safe-to-use virus-like objects, which imitate real viruses and allow performing virus-related studies in any research laboratory, constitutes an important scientific challenge. Such species, called virus-like particles (VLPs), contain instead of capsids with viral DNA/RNA empty or synthetic cores with real virus proteins attached to them. We have developed a method for the preparation of VLPs imitating the virus responsible for the COVID-19 disease: the SARS-CoV-2. The particles have Au cores surrounded by "coronas" of S1 domains of the virus's spike protein. Importantly, they are safe to use and specifically interact with SARS-CoV-2 antibodies. Moreover, Au cores exhibit localized surface plasmon resonance (LSPR), which makes the synthesized VLPs suitable for biosensing applications. During the studies, the effect allowed us to visualize the interaction between the VLPs and the antibodies and identify the characteristic vibrational signals. What is more, additional functionalization of the particles with a fluorescent label revealed their potential in studying specific virus-related interactions. Notably, the universal character of the developed synthesis method makes it potentially applicable for fabricating VLPs imitating other life-threatening viruses.

Magnetic patterning of Co/Ni layered systems by plasma oxidation

We studied the structural, chemical, and magnetic properties of Ti/Au/Co/Ni layered systems subjected to plasma oxidation. The process results in the formation of NiO at the expense of metallic Ni, as clearly evidenced by X-ray photoelectron spectroscopy, while not affecting the surface roughness and grain size of the Co/Ni bilayers. Since the decrease of the thickness of the Ni layer and the formation of NiO increase the perpendicular magnetic anisotropy, oxidation may be locally applied for magnetic patterning. Using this approach, we created 2D heterostructures characterized by different combinations of magnetic properties in areas modified by plasma oxidation and in the regions protected from oxidation. As plasma oxidation is an easy to use, low cost, and commonly utilized technique in industrial applications, it may constitute an improvement over other magnetic patterning methods.

Ammonium Gemini Surfactants Form Complexes with Model Oligomers of siRNA and dsDNA

Dimeric cationic surfactants (gemini-type) are a group of amphiphilic compounds with potential use in gene therapy as effective carriers for nucleic acid transfection (i.e., siRNA, DNA, and plasmid DNA). Our studies have shown the formation of lipoplexes composed of alkanediyl-α,ω-bis[(oxymethyl)dimethyldodecylammonium] chlorides and selected 21-base-pair nucleic acid (dsDNA and siRNA) oligomers. To examine the structure and physicochemical properties of these systems, optical microscopy, circular dichroism spectroscopy (CD), small-angle X-ray scattering of synchrotron radiation (SR-SAXS), and agarose gel electrophoresis (AGE) were used. The lengths of spacer groups of the studied surfactants had a significant influence on the surfactants’ complexing properties. The lowest charge ratio (p/n) at which stable lipoplexes were observed was 1.5 and the most frequently occurring microstructure of these lipoplexes were cubic and micellar phases for dsDNA and siRNA, respectively. The cytotoxicity tests on HeLa cells indicated the non-toxic concentration of surfactants to be at approximately 10 µM. The dicationic gemini surfactants studied form complexes with siRNA and dsDNA oligomers; however, the complexation process is more effective towards siRNA. Therefore these systems could be applied as transfection systems for therapeutic nucleic acids.

Structural characterization of transfection nanosystems based on tricationic surfactants and short double stranded oligonucleotides

For several years cationic surfactants have been the subjects of extensive studies as potential transgene carriers to be used in gene therapy. We report the formation of stable complexes between 21 base pairs oligonucleotides - siRNA, enhancing DMPK gene, and dsDNA and two tricationic surfactants (1,2,3-propanetri[oxymethyl-3-(1-dodecylimidazolium)]chloride and 1,2,3-propanetri[(oxymethyl)dimethyldodecylammonium]chloride. Structural studies by SAXS and TEM have shown that the dominant structure of the obtained lipoplexes is based on hexagonal, lamellar and cubic phases, packed in highly ordered aggregates. It has been established that tricationic surfactants can be used as siRNA carriers in gene therapy.

The study of complexation between dicationic surfactants and the DNA duplex using structural and spectroscopic methods

Dicationic (also known as gemini or dimeric) bis-alkylimidazolium surfactants belong to a group of non-viral transfection systems proposed for the successful introduction of different types of nucleic acids (i.e., siRNA, DNA oligomers, and plasmid DNA) into living cells.

[Results of retinal detachment surgery in aphakic and pseudo-aphakic eyes]

PURPOSE

The authors present results of conventional treatment of a patient with the retinal detachment in the aphakic and pseudophakic eyes.

MATERIAL AND METHODS

The group consisted of 34 persons: 10 women and 24 men, aged from 40-79 years. Earlier the intracapsular (in 24 eyeballs) and extracapsular (in 3 eyeballs), lens extraction had been performed. The intraocular lens was inserted into 7 eyes. The following surgical technics were performed: cerclage in 16 eyes, screlar invagination in 5 eyes, scleral invagination with an extrascleral implant in 7 eyes, the extrascleral implant alone in 6 eyes.

RESULTS

Total retinal reattachment was attained in 85% in aphakic eyes and 100% in pseudophakic eyes.

[The different aspects of ophthalmological disability on the own experience]

PURPOSE

The purpose of the study was to present the most often reasons of ophthalmological invalidity.

MATERIAL

The analysis was based on 154 court's opinions.

RESULTS

Monopia, high myopia and different congenital diseases were the most frequent reasons of ophthalmological invalidity.

[Treatment of infantile strabismus with eye movement disorders]

PURPOSE

Possibilities of application of localization method in the treatment of infantile strabismus in a very early period are presented.

MATERIAL AND METHODS

The authors applied treatment with hypercorrective and compensating prisms in 17 children with infantile strabismus. The age of the children ranged from 0.5 to 5 years, mean age-1 year. All children were found to have no motility or limited motility of eyes toward the temples. Initially, the children's eyes were alternately occluded in prisms whose strength prevalently was 30-40 pr dptr before each eye, with base toward the temple. After 1-3 months motility of the eyes appeared. Next, glasses compensating the squint angle were worn, without covering the eyes, starting with 1/2 hour 3 times a day and gradually prolonging the wearing time. Hypercorrective prisms were further used with alternate occlusion of the eyes.

RESULTS

In all children partial or complete correction of motility was achieved. Further treatment of strabismus followed the rules of the localization method.

[Changes in the visual system of patients with carotid artery occlusion]

The authors presented results of visual system examination in 28 persons in whom disturbances of blood flow in carotid arteries were diagnosed with colour doppler ultrasonography. The patients underwent routine ophthalmological examination, including kinetic and static perimetry. Ocular signs only, with no neurological changes, were found in 46% of patients. In 21% of cases there were episodes of transient blindness; homonymous hemianopsia occurred in 10%, acute ischaemic optic neuropathy in 11%, and secondary neovascular glaucoma in 14% of patients.

[Individual choice of treatment in patients with progressive infiltrative ophthalmopathy in Graves-Basedow disease]

The results of different methods of treatment of infiltrative endocrine ophthalmopathy in 68 patients (52 women and 16 men) aged 28-63 years were evaluated. The analysis of the results indicates that combined treatment with glucocorticoids and tele-cobalt therapy may be considered as the method of choice. In patients with rapidly progressive ophthalmopathy and in patients with inactive peptic ulcer intravenous pulsed glucocorticoid administration may be used instead of oral treatment. When contraindications to corticotherapy exist, good results of treatment may be achieved with tele-cobalt therapy alone. Plasmapheresis seems less effective but may be used in rapidly progressive, short term lasting ophthalmopathy in patients refusing tele-cobalt therapy, in connection with glucocorticoids or after unsuccessful glucocorticoid therapy alone. The consecutive treatment with glucocorticoids and tele-cobalt therapy is effective but requires much more time.

[Analysis of early and late results of progressive Graves-Basedow ophthalmopathy treatment with different methods]

The early (immediately after the end of treatment) and late (from 12 to 91, mean 46.3 months after the end of treatment) results of progressive Graves-Basedow ophthalmopathy treatment were evaluated in 71 patients (57 women and 14 men, aged 25-66, mean 47.3 years). In all patients the thorough ophthalmological evaluation was performed early and late after treatment and the abnormalities found were classified according to Werner's method and Donaldson's ophthalmopathy index. The patients were divided into 7 groups according to different methods of treatment. Groups I-V consisted of 31 patients treated with glucocorticoids or glucocorticoids with azathioprine (Imuran) in the first stage of medication (30 patients). Plasmapheresis (7 patients) or tele-cobalt irradiation (3 patients) was applied as the second stage of treatment when the first stage was ineffective. In one person plasmapheresis and tele-cobalt irradiation was applied without previous glucocorticoid therapy. Two patients were treated successively by glucocorticoids, plasmapheresis and tele-cobalt irradiation. Very good and good late results of treatment were found in 95% of patients out of 22 reexamined persons of groups 1-5. Group 6 consisted of 7 patients treated with cobalt irradiation alone, in all 6 patients evaluated late results were good or very good. Out of 33 patients of group 7 treated by combination of glucocorticoids and telecobalt irradiation 23 were evaluated late and the results were found good or very good in 96%. The results suggest that combined treatment of progressive endocrine ophthalmopathy with glucocorticoids and cobalt irradiation is the most effective method of treatment at present. The affectivity of stage treatment is comparable with combined treatment but lasts longer and usually is more expansive.(ABSTRACT TRUNCATED AT 250 WORDS)

[Titers of antibodies against thyroid membrane antigens in patients with Graves-Basedow disease and progressive infiltrative ophthalmopathy during treatment with glucocorticoids and retro-orbital tissue irradiation]

In 22 patients with progressive endocrine ophthalmopathy (classes 4-6 according to Werner's scale and ophthalmopathy index at least 4 and evidences of infiltrative changes in retro-ocular tissues in computerised tomography, after achievement of euthyroid state) the titers of antibodies against thyroid membrane antigens (ATMA) were determined by Gardas and all. method. Control group consisted of 26 patients with Graves-Basedow disease without clinical signs of ophthalmopathy who were investigated for ATMA before and after conventional methimazole treatment. The determinations of ATMA were performed before treatment, after 3-4 weeks and subsequently once a month. ATMA's titers exceeding 1:1000 were found in 68% of patients with progressive infiltrative ophthalmopathy and in 77% of patients with Graves-Basedow disease without ophthalmopathy. The incidence of elevated ATMA titers during treatment of ophthalmopathy with supervoltage retro-orbital tissues irradiation with high dose of prednisone, decreased markedly in 6th month of treatment with subsequent increase to average 55% at the end of treatment what suggests the influence of therapy on antibodies production. The changes in the incidence of elevated ATMA titers during conventional Graves-Basedow disease treatment were different. No relations between increased ATMA titers and intensity of infiltrative ophthalmopathy and the course of treatment in the patients with ophthalmopathy were found.

[Laser therapy of ocular toxoplasmosis]

The authors present the results of treatment by laser coagulation of inflammatory retino-choroidal foci in 32 persons with ocular toxoplasmosis. The diagnosis of Toxoplasma etiology was set on a basis of positive immunological reaction for Toxoplasma gondii antigen and after exclusion of other etiological factors. Among 42 eyes stabilization of the process after 1 intervention was observed in 34, i.e. in 89 p.c. (period of observation--up to 4 years). In the following 8 eyes arised the necessity to perform additional coagulations because of formation of fresh foci which appeared in 5 eyes after 6 months, in 2 eyes after 1 year and in 1 eye after 2 years since onset. The authors consider the application of laser coagulation in ocular toxoplasmosis as a favourable method together--or independently--with pharmacological treatment.

[Analysis of early results of combined treatment with glucocorticoids and telecobalt therapy for Graves' disease ophthalmopathy]

Early results of combined use of glucocorticoid administration and irradiation with radioactive cobalt for treatment of oedematous-infiltrative ophthalmopathy associated with Graves' disease have been analyzed in a group of 33 patients including 28 women and 5 men of age between 25 and 66 years (mean age 47.3 years). The combined therapy was a modification of the original method of Bartalena et al. which consisted in the gradual increase of the initial dose of glucocorticoids and prolongation of the period of administration of the drug. The ophthalmic lesions were assessed by thorough ophthalmologic examination and classified according to Werner. The ophthalmopathy index was calculated according to Donaldson. Satisfactory results of treatment have been obtained in 32 patients, with 9 patients being completely relieved from any objective or subjective ophthalmic symptoms (very good results), and 23 patients having still small afflictions originating from the soft tissues of the eye socket, exophthalmos, diplopia during marginal vision and a decreased visual acuity (good results). The clinical recovery was mostly connected with the improvement in the condition of soft tissues of the eye socket, cornea and external ocular muscles and, to a smaller extent, exophthalmos which persisted to some degree and acuity of vision not always attaining normal values. In one person the results of treatment were unsatisfactory despite some improvement. Very good and good results obtained in 97% of patients indicate that the administration of glucocorticoids combined with the irradiation of retrobulbar tissues with radioactive cobalt can now be regarded as the most effective method of treatment of the progressive oedematous-infiltrative ophthalmopathy.

[Prevention of retinal detachment. I. Cryopexy before cataract extraction. Preliminary report]

The authors discuss the results of cryopexy applied prophylactically in 32 eyes. The freezing was executed at least 6 weeks before the cataract extraction in eyes endangered by retinal detachment. This were the high myopia eyes, so called fellow eyes and eyes in persons aged between 30 and 40 years. Retinal detachment did not occur in either of the observed eyes in the period of 1-5 years.

Age-related changes in the extracellular matrix of the human optic nerve head

By using immunofluorescent staining we were able to characterize the age-related changes in the macromolecules making up the extracellular matrix of the lamina cribrosa of the human optic nerve head. As the cores of the cribriform plates enlarged with age, there were age-related increases in the apparent density of collagen types I and III and elastin that constituted the connective tissue support of the nerve bundles. Collagen type IV coated the cribriform plates as basement membranes and was also present within the cores as a fine filamentous network, which increased in density with age as the cribriform plates expanded. As this tissue ages, individual differences leading to more or less of a particular macromolecule of the extracellular matrix may alter the support function of the lamina cribrosa and influence the degeneration of the optic nerve associated with glaucoma.

[Late results of goniotrephining using the Elliot-Fronimopoulos method]

One hundred and four eyes were operated in 86 patients: 65 eyes with an open angle glaucoma, 20 eyes with narrow or closed angle glaucoma and 19 eyes with secondary glaucoma. Normalization of the IOP was attained in 72.4 p.c. of patients from the 1st group, in 90 p.c. from the 2nd and in 57 p.c. from the 3rd group; after an additional pharmacological treatment respectively in 98.5 p.c., 100 p.c. and 89.5 p.c. Normal visual acuity or an improvement was observed in 75.4 p.c. of patients from the 1st group, in 60 p.c. from the 2nd and in 57.9 p.c. from the 3rd group. The visual field deteriorated in 23.2 p.c. of patients from the 1st group, in 25 p.c. from the second one and in 31.5 p.c. from the 3rd group. The good results obtained are encouraging for the employment of the Elliot-Fronimopoulos operation in all types of glaucoma.