Rhipicephalus microplus and its vector-borne haemoparasites in Guinea: further species expansion in West Africa.

Rhipicephalus microplus is an ixodid tick with a pantropical distribution that represents a serious threat to livestock. West Africa was free of this tick until 2007, when its introduction into Benin was reported. Shortly thereafter, further invasion of this tick species into other West African countries was identified. In this paper, we describe the first detection of R. microplus in Guinea and list the vector-borne haemoparasites that were detected in the invading and indigenous Boophilus species. In 2018, we conducted a small-scale survey of ticks infesting cattle in three administrative regions of Guinea: N`Zerekore, Faranah, and Kankan. The tick species were identified by examining their morphological characteristics and by sequencing their COI gene and ITS-2 gene fragments. R. microplus was found in each studied region. In the ticks, we found the DNA of Babesia bigemina, Anaplasma marginale, Anaplasma platys, and Ehrlichia sp. The results of this study indicate that R. microplus was introduced into Guinea in association with cows from Mali and/or the Ivory Coast.

Bombali Virus in Mops condylurus Bats, Guinea.

In 2018, a previously unknown Ebola virus, Bombali virus, was discovered in Sierra Leone. We describe detection of Bombali virus in Guinea. We found viral RNA in internal organs of 3 Angolan free-tailed bats (Mops condylurus) trapped in the city of N'Zerekore and in a nearby village.

Effect of morphology of nanoscale hydrated channels on proton conductivity in block copolymer electrolyte membranes.

Hydrated membranes with cocontinuous hydrophilic and hydrophobic phases are needed to transport protons in hydrogen fuel cells. Herein we study the water uptake and proton conductivity of a model fuel cell membrane comprising a triblock copolymer, polystyrenesulfonate-block-polyethylene-block-polystyrenesulfonate (S-SES), as a function of water activity in both humid air and liquid water. We demonstrate that the water uptake and proton conductivity of S-SES membranes equilibrated in liquid water are fundamentally different from values obtained when they were equilibrated in humid air. The morphological underpinnings of our observations were determined by synchrotron small-angle X-ray scattering and cryogenic scanning transmission electron microscopy. A discontinuous increase in conductivity when nearly saturated humid air is replaced with liquid water coincides with the emergence of heterogeneity in the hydrated channels: a water-rich layer is sandwiched between two polymer-rich brushes. While the possibility of obtaining heterogeneous hydrated channels in polymer electrolyte membranes has been discussed extensively, to our knowledge, this is the first time that direct evidence for the formation of water-rich subdomains is presented.

Complete genome sequence of Chlamydia psittaci АМК-16, isolated from a small ruminant in the Middle Volga Region, Russia.

We report the complete genome sequence of the Chlamydia psittaci АМК-16, recovered from the aborted caprine fetus during a case of chlamydia infection. This 1,152,497-bp genome with 7,552-bp cryptic plasmid provides novel insights into the genetic diversity of chlamydia agent strains particularly those causing the infection in small ruminants.

Cell attachment on poly(3-hydroxybutyrate)-poly(ethylene glycol) copolymer produced by Azotobacter chroococcum 7B.

BACKGROUND: The improvement of biomedical properties, e.g. biocompatibility, of poly(3-hydroxyalkanoates) (PHAs) by copolymerization is a promising trend in bioengineering. We used strain Azotobacter chroococcum 7B, an effective producer of PHAs, for biosynthesis of not only poly(3-hydroxybutyrate) (PHB) and its main copolymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-HV), but also alternative copolymer, poly(3-hydroxybutyrate)-poly(ethylene glycol) (PHB-PEG). RESULTS: In biosynthesis we used sucrose as the primary carbon source and valeric acid or poly(ethylene glycol) 300 (PEG 300) as additional carbon sources. The chemical structure of PHB-PEG and PHB-HV was confirmed by 1H nuclear-magnetic resonance (1H NMR) analysis. The physico-chemical properties (molecular weight, crystallinity, hydrophilicity, surface energy) and surface morphology of films from PHB copolymers were studied. To study copolymers biocompatibility in vitro the protein adsorption and COS-1 fibroblasts growth on biopolymer films by XTT assay were analyzed. Both copolymers had changed physico-chemical properties compared to PHB homopolymer: PHB-HV and PHB-PEG had less crystallinity than PHB; PHB-HV was more hydrophobic than PHB in contrast to PHB-PEG appeared to have greater hydrophilicity than PHB; whereas the morphology of polymer films did not differ significantly. The protein adsorption to PHB-PEG was greater and more uniform than to PHB and PHB-PEG copolymer promoted better growth of COS-1 fibroblasts compared with PHB homopolymer. CONCLUSIONS: Thus, despite low EG-monomers content in bacterial origin PHB-PEG copolymer, this polymer demonstrated significant improvement in biocompatibility in contrast to PHB and PHB-HV copolymers, which may be coupled with increased protein adsorption and hydrophilicity of PEG-containing copolymer.

Visualization of clusters in polymer electrolyte membranes by electron microscopy.

The morphology of ionic clusters that form in polyelectrolyte membranes has a strong effect on transport and electrical properties. In spite of considerable research effort the link between morphology and properties has not been clearly established, mainly due to difficulties in assessing nanoscale morphology. Electron microscopy (EM) has the potential to visualize morphology. However success in visualization has so far been moderate. In this review we focus on the potential of EM techniques to characterize the ionic domains. We use both experimental data and models to compare the capabilities of several EM techniques: BF TEM, HAADF, core-loss EELS, and low-loss EELS in projection imaging and STEM modes. The main problems common for all these EM modes are radiation damage and overlap of features in projection. Our models show that core loss EELS with exposures that are below the typical damage threshold is incapable of resolving 2 nm diameter sulfur-rich clusters in PEMs. While low loss EELS requires lower exposure, the insight it can provide is quite limited. HAADF and BF TEM present the most effective modes for imaging the sulfur clusters in PEMs. While BF TEM uses scattered electrons more efficiently, HAADF using slightly higher doses can provide unique information due to in-focus imaging and transparent interpretation of the images. Fortunately, in at least some interesting cases the clusters themselves are much more radiation resistant than the polymer and can be studied at exposures high enough to obtain clear images. Our simulations also show that tomographic 3D reconstruction provides the best approach for solving the overlap problem. In spite of the abilities of electron tomography, data obtained from all EM techniques improve if thin sections are studied. We briefly discuss methods for obtaining such sections.

Epidemiology of Zoonotic Coxiella burnetii in The Republic of Guinea.

BACKGROUND: Q fever is a zoonotic infectious disease characterized by fever, malaise, chills, significant weakness, and muscle pain. In some cases, the disease can become chronic and affect the inner membranes of the heart, such as the valves, leading to endocarditis and a high risk of death. Coxiella burnetii (C. burnetii) is the primary causative agent of Q fever in humans. This study aims to monitor the presence of C. burnetii in ticks collected from small mammals and cattle in the Republic of Guinea (RG). METHODS: Rodents were trapped in the Kindia region of RG during 2019-2020, and ticks were collected from cattle in six regions of RG. Total DNA was extracted using a commercial kit (RIBO-prep, InterLabService, Russia) following the manufacturer's instructions. Real-time PCR amplification was conducted using the kit (AmpliSens Coxiella burnetii-FL, InterLabService, Russia) to detect C. burnetii DNA. RESULTS AND CONCLUSIONS: Bacterial DNA was detected in 11 out of 750 (1.4%) small mammals and 695 out of 9620 (7.2%) tick samples. The high number of infected ticks (7.2%) suggests that they are the main transmitters of C. burnetii in RG. The DNA was detected in the liver and spleen of a Guinea multimammate mouse, Mastomys erythroleucus. These findings demonstrate that C. burnetii is zoonotic in RG, and measures should be taken to monitor the bacteria's dynamics and tick prevalence in the rodent population.

Diversion-p64: results from an international, prospective, multicenter, single-arm post-market study to assess the safety and effectiveness of the p64 flow modulation device.

BACKGROUND: The use of flow diversion to treat intracranial aneurysms has increased in recent years. OBJECTIVE: To assess the safety and angiographic efficacy of the p64 flow modulation device. METHODS: Diversion-p64 is an international, prospective, multicenter, single-arm, study conducted at 26 centers. The p64 flow modulation device was used to treat anterior circulation aneurysms between December 2015 and January 2019. The primary safety endpoint was the incidence of major stroke or neurologic death at 3-6 months, with the primary efficacy endpoint being complete aneurysm occlusion (Raymond-Roy Occlusion Classification 1) on follow-up angiography. RESULTS: A total of 420 patients met the eligibility criteria and underwent treatment with the p64 flow modulation device (mean age 55±12.0 years, 86.2% female). Mean aneurysm dome width was 6.99±5.28 mm and neck width 4.47±2.28 mm. Mean number of devices implanted per patient was 1.06±0.47, with adjunctive coiling performed in 14.0% of the cases. At the second angiographic follow-up (mean 375±73 days), available for 343 patients (81.7%), complete aneurysm occlusion was seen in 287 (83.7%) patients. Safety data were available for 413 patients (98.3%) at the first follow-up (mean 145±43 days) with a composite morbidity/mortality rate of 2.42% (n=10). CONCLUSIONS: Diversion-p64 is the largest prospective study using the p64 flow modulation device. The results of this study demonstrate that the device has a high efficacy and carries a low rate of mortality and permanent morbidity.

Direct imaging of nanoscale acidic clusters in a polymer electrolyte membrane.

One of the factors hindering the development of technologies that rely on the use of proton-conducting polyelectrolyte membranes is the lack of control over the membrane morphology on the nanoscale. Of particular importance is the rearrangement and clustering of acidic groups, which may seriously degrade the electrical properties. Although electron microscopy is capable of imaging the morphology of the clusters, images of unmodified membranes with sufficient quality to discriminate between different proposed cluster morphology models have not been presented. Here we show the first determination of the cluster size distribution in a model polymer electrolyte membrane from electron micrographs of individual acidic clusters. Imaging of the sulfur-rich clusters by dark-field microscopy was facilitated by the spontaneous formation of thin, cluster-containing layers on the top and bottom surfaces of free-standing films with a thickness of ~35 nm.

Advanced craniofacial juvenile nasopharyngeal angiofibroma. Description of surgical series, case report, and review of literature.

BACKGROUND: Juvenile nasopharyngeal angiofibroma (JNA) is a rare benign tumor occurring almost exclusively in adolescent and young adult males. The tumor is characterized by slow progression, aggressive growth, high vascularization, and increased rate of persistence and recurrence. The aim of this study was to describe a case of giant JNA from our practice and discuss the controversies of surgical treatment of advanced JNA. MATERIAL AND METHODS: A series of 29 consecutive male patients with JNA Fisch grade III and IV was surgically treated in Burdenko Neurosurgical Institute from 2000 until 2008. In the vast majority of cases, endovascular embolization and surgical removal via orbitozygomatic approach were applied. RESULTS: Gross total resection was achieved in 24 cases (83%). Complications were encountered in eight cases. No mortality was observed. In three patients, the diseases recurred. An illustrative case is described. CONCLUSION: Surgical treatment is the basic tactics in management of extensive JNA including endovascular embolization and resection of the tumor. We recommend using orbitozygomatic approach or its modifications in JNA. Radiation therapy may be recommended for patients with small residual tumor.

Treatment of postoperative vasospasm with intraarterial verapamil after removal of intracranial tumor: patient series.

BACKGROUND: The authors report on four clinical cases with intraarterial verapamil administration to resolve vasospasm in patients who underwent surgery for intracranial tumors. Iatrogenic subarachnoid hemorrhage after tumor resection and subsequent vasospasm (an increase in the systolic linear velocity of blood flow through the M1 segment of the middle cerebral artery of more than 250 cm/sec; Lindegaard index: 4.1) were observed in four patients during the early postoperative period after the removal of intracerebral tumors. Each vasospasm case was confirmed by angiography data, was clinically significant, and manifested as the development of a neurological deficit. OBSERVATIONS: Resolution of vasospasm with the intraarterial administration of verapamil was achieved in all four cases as confirmed by angiographic data in all four cases and complete regression of neurological symptoms in two cases. In all four presented cases, vasospasm was resolved; unfortunately, the resolution did not always lead to significant clinical improvement. However, lethal outcomes were avoided in two cases, and almost full recoveries were achieved in the other two. LESSONS: The authors believe that the removal of intracranial tumors can cause expected and potential complications, such as cerebral vasospasm, which must be diagnosed and treated in a timely manner.

Detection of Babesia caballi, Theileria mutans and Th. velifera in ixodid ticks collected from cattle in Guinea in 2017-2018.

Intraerythrocytic protozoan parasites from the genera Babesia and Theileria may infect a wide range of animals and humans. The purpose of this study was to detect the 18S ribosomal RNA gene of Babesia spp. and Theileria spp. in ticks collected from household cows in the Republic of Guinea from 2017 to 2018 by PCR and then genotype the gene fragments by sequencing. A total of 907 ticks from 319 cows were collected in seven prefectures of Guinea (Boke, Faranah, Kankan, Kindia, Labe, Mamou and N'Zerekore). The following tick species on cattle were identified: Amblyomma variegatum (44.2%), Rhipicephalus decoloratus (34.7%), Rh. annulatus (10.3%), Rh. geigyi (7.3%) Hyalomma truncatum (2.4%), Rh. senegalensis (0.8%) and Haemaphysalis leachi (0.6%). Genetic markers for piroplasms were found in Am. variegatum, Rh. decoloratus, Rh. annulatus, and Rh. geigyi ticks, and the total infection rate for these ticks was 4.2%. The highest infection rate was found in Rh. annulatus ticks (10.9%). The piroplasms were genotyped as Babesia caballi, Theileria mutans and Theileria velifera by phylogenetic analysis of the 1150 bp 18S ribosomal RNA gene fragments. These pathogens were discovered in practically all studied prefectures in Guinea except for Mamou Prefecture. We propose that these ixodid ticks might play a major role in the transmission of piroplasm infections in domestic animals in Guinea.

Ngari virus (Orthobunyavirus, Peribunyaviridae) in ixodid ticks collected from cattle in Guinea.

Ngari virus is a mosquito-borne virus belonging to the genus Orthobunyavirus (Peribunyaviridae family). This virus is pathogenic to humans and causes severe illness. Ngari virus is present in several African countries, including Madagascar. Here, we report the detection of Ngari virus in ixodid ticks collected from cows in Guinea. A tick survey was conducted in March-November of 2018 in six regions of Guinea. The sample comprised 710 pools, with a total of 2067 ticks belonging to five species collected from 197 cows. At the initial stage, we screened a subsample of tick pools of vector-borne viruses with a multiplex genus-specific primer panel. In the second stage of the study, we narrowed the search and screened all the samples by qPCR for the detection of Ngari virus. All positive samples were sequenced with primers flanking Ngari virus-specific fragments on the S and M segments. We found Ngari virus in 12 pools that were formed from engorged ticks collected from livestock in three villages of the Kindia and Kankan regions. Sequencing of the S and M segments confirmed that the detected viruses belong to Ngari virus, and the viruses were most similar to the strain Adrar, which was isolated in Mauritania. We detected viral RNA in ticks of the following species: Amblyomma variegatum, Rhipicephalus geigyi, and Rh. (Boophilus) spp. There is no evidence that ixodid ticks are competent vectors of the Ngari virus. Most likely, the ticks obtained the virus through blood from an infected host. The study of engorged ticks can be recommended as a simpler approach for the wide screening of the Ngari virus and subsequent testing of cattle and mosquitos in those locations where the PCR-positive ticks were collected.

Optimized packing multidimensional hyperspheres: a unified approach.

In this paper an optimized multidimensional hyperspheres packing problem (HPP) is considered for a bounded container. Additional constraints, such as prohibited zones in the container or minimal allowable distances between spheres can also be taken into account. Containers bounded by hyper- (spheres, cylinders, planes) are considered. Placement constraints (non-intersection, containment and distant conditions) are formulated using the phi-function technique. A mathematical model of HPP is constructed and analyzed. In terms of the general typology for cutting & packing problems, two classes of HPP are considered: open dimension problem (ODP) and knapsack problem (KP). Various solution strategies for HPP are considered depending on: a) objective function type, b) problem dimension, c) metric characteristics of hyperspheres (congruence, radii distribution and values), d) container's shape; e) prohibited zones in the container and/or minimal allowable distances. A solution approach is proposed based on multistart strategies, nonlinear programming techniques, greedy and branch-and-bound algorithms, statistical optimization and homothetic transformations, as well as decomposition techniques. A general methodology to solve HPP is suggested. Computational results for benchmark and new instances are presented.

Distribution and antibiotic resistance profile of key Gram-negative bacteria that cause community-onset urinary tract infections in the Russian Federation: RESOURCE multicentre surveillance 2017 study.

BACKGROUND: Urinary tract infections (UTIs) are among the most common bacterial infections in clinical practice. This RESOURCE (pathogen distribution and antibiotic RESistance prOfile of key Gram-negative bacteria caUsing community-onsEt URinary traCt) study aimed to determine the antimicrobial resistance profile of Gram-negative bacteria isolated from outpatient urine samples collected across the Russian Federation. METHODS: A total of 96 781 urine samples were collected from 520 cities in the Russian Federation between 01 January 1 and 31 December 2017. Antibiotic susceptibility was performed using semi-automated analysers. The mean age of the study population was 40.9 years; 80.2% were female and 19.8% were male. RESULTS: Of the uropathogens that were isolated, 64.2% were Gram-negative bacteria. Among these, Escherichia coli (E. coli) was the most common (49.1%) followed by Klebsiella pneumoniae (9.5%), Proteus mirabilis (2.9%), Pseudomonas aeruginosa (1.7%), and Enterobacter spp. (1.0%). Of the antibiotics that were tested, 50% of the isolated E. coli strains were resistant to ampicillin, 30.3% to co-trimoxazole, 26.2% to aztreonam, 28.8% to levofloxacin, and 21% to cefuroxime. Conversely, E. coli was highly susceptible to imipenem (0.7% resistant strains isolated), amikacin (0.9%), nitrofurantoin (4.5%), and fosfomycin (1.2%). The most active antimicrobials against Klebsiella pneumoniae were imipenem (6.8% resistant strains) and colistin (0.5%), while piperacillin/tazobactam (4.2%), cefoperazone/sulbactam (3.1%) and imipenem (0%) were the most active agents against Proteus mirabilis. The antimicrobials showing the highest activity against Pseudomonas aeruginosa were colistin (10.7% resistant strains) and aztreonam (0%), while piperacillin/tazobactam (7.1%) and cefoperazone/sulbactam (2.3%) showed the highest activity against Enterobacter spp. CONCLUSION: The prevalence of fluoroquinolone and cephalosporin resistance among common UTI-causing Gram-negative bacteria highlights the growing challenge of successfully treating community-onset UTIs.

Data of de novo genome assembly of the Chlamydia psittaci strain isolated from the livestock in Volga Region, Russian Federation.

Chlamydiae are obligate intracellular bacteria globally widespread across humans, wildlife, and domesticated animals. Chlamydia psittaci is a primarily zoonotic pathogen with multiple hosts, which can be transmitted to humans, resulting in psittacosis or ornithosis. Since this pathogen is a well-recognized threat to human and animal health, it is critical to unravel in detail the genetic make-up of this microorganism. Though many genomes of C. psittaci have been studied to date, little is known about the variants of chlamydial organisms causing infection in Russian livestock. This research is the first de novo genome assembly of the C. psittaci strain Rostinovo-70 of zoonotic origin that was isolated in Russian Federation. The results were obtained by using standard protocols of sequencing with the Illumina HiSeq 2500 and Oxford Nanopore MinION technology that generated 3.88 GB and 3.08 GB of raw data, respectively. The data obtained are available in NCBI DataBase (GenBank accession numbers are CP041038.1 & CP041039.1). The Multi-Locus Sequence Typing (MLST) showed that the strain Rostinovo-70 together with C. psittaci GR9 and C. psittaci WS/RT/E30 belong to the sequence type (ST)28 that could be further separated into two different clades. Despite C. psittaci Rostinovo-70 and C. psittaci GR9 formed a single clade, the latter strain did not contain a cryptic plasmid characteristis to Rostinovo-70. Moreover, the genomes of two strains differed significantly in the cluster of 30 genes that in Rostinovo-70 were closer to Chlamydia abortus rather than C. psittaci. The alignment of the genomes of C. psittaci and C. abortus in this area revealed the exact boarders of homologous recombination that occurred between two Chlamydia species. These findings provide evidence for the first time of genetic exchange between closely related Chlamydia species.

Dose-limited spectroscopic imaging of soft materials by low-loss EELS in the scanning transmission electron microscope.

Spectroscopic imaging in the scanning transmission electron microscope (STEM) using spatially resolved electron energy-loss spectroscopy (EELS) provides one of the few ways to quantitatively measure the real-space nanoscale morphology of soft materials such as polymers and biological tissue. This paper describes the basic principles of this technique and outlines some of the important attributes that define the achievable spatial resolution. Many soft materials can be differentiated from each other as well as from solvents based on their EELS fingerprints. Applying a multiple least squares (MLS) fitting algorithm using such spectral fingerprints to analyze spatially resolved spectrum datasets enables the quantitative mapping of the different components in a specimen. However, in contrast to TEM studies of many inorganic materials where the spatial resolution is limited principally by the spherical aberration of the objective lens, the spatial resolution associated with the imaging of radiation-sensitive soft materials is limited by the total electron dose to which they can be exposed before suffering irrevocable chemical or structural damage. The Rose criterion provides a simple guide to enhance the so-called dose-limited spatial resolution relevant to soft-materials imaging. By using the low-loss portion of an EELS spectrum where the inelastic scattering cross-sections are highest together with improvements in data-collection efficiency and post-acquisition data processing, the dose-limited resolution in spectrum images of solvated polymers has moved into the sub 10nm regime. This resolution is sufficient to solve important applications-oriented problems associated with hetero interfaces, nanoscale mixing, and nanophase separation.

Treatment of Brain Arteriovenous Malformations with Hemodynamic Aneurysms: A Series of 131 Consecutive Cases.

BACKGROUND: The natural history of hemodynamic aneurysms (HAs) associated with brain arteriovenous malformations (AVMs) remains controversial, with no single approach to treatment. The purpose of this study was to justify preventive treatment tactics for HAs that pose an increased risk of rupture based on hemodynamic studies demonstrating hypertension in the afferent bed after AVM exclusion. METHODS: This retrospective analysis included 131 of 1740 patients (8%) with brain AVMs and at least 1 aneurysm treated at Burdenko Neurosurgical Institute between 2000 and 2016. Treatment consisted of microsurgery, endovascular interventions, or a combination of modalities. Patients were evaluated with the modified Rankin Scale before and after treatment. RESULTS: A total of 205 aneurysms were discovered. Multiple HAs were found in 46 patients (35%), and were significantly more often associated with posterior fossa AVMs; in addition, most were distally located. There was no difference in the incidence of hemorrhage between proximal and distal HAs. Microsurgical treatment was marked by high radicalism; 85% of HAs and 94% of AVMs were totally excluded based on control studies. In 10 cases, aneurysms were found after AVM removal, including 4 de novo aneurysms. In 1 case, the aneurysm regressed after AVM treatment. The mortality rate was 2.3%. CONCLUSIONS: Preoperative imaging should be carefully examined for associated aneurysms before and after surgical treatment. Our data suggests that HA exclusion, either as the first step or simultaneously with AVM treatment, is most beneficial to patients.

Preclinical Toxicity of Paclitaxel Biopolymer Formulation.

BACKGROUND: Poly(hydroxyalkanoates) (PHA) have recently attracted increasing attention due to their biodegradability and high biocompatibility, which makes them suitable for the development of new prolong drug formulations. OBJECTIVE: A preclinical toxicology study of paclitaxel biopolymer formulation (PBF) (paclitaxel-loaded poly(3- hydroxybutyrate) (PHB) microparticles) was done in order to assess its safety and to forecast side and toxic effects in a clinical study on patients. METHOD: PHB microparticles loaded with antitumor cytostatic drug PTX were obtained by spray-drying method using Nano Spray Dryer B-90. The comprehensive study of cytotoxicity (on bone marrow stem cells), acute and chronic toxicity, allergenic and pyrogenic properties, histological investigation (in mice, rats and rabbits) of obtained PBF was carried out. RESULTS: The acute toxicity study showed that PBF is much less toxic in equivalent PTX-content doses than PTX in conventional formulation when administered intraperitoneally to mice and rats. However, the chronic toxicity study showed that at intraperitoneal administration PBF has distinct cumulative properties and toxic effects that prevent PBF from clinical testing in current composition. CONCLUSION: Thus, the PBF as a prolong drug needs to correct its parameters for further drug formulation development.

New Poly(3-hydroxybutyrate) Microparticles with Paclitaxel Sustained Release for Intraperitoneal Administration.

BACKGROUND: Poly(hydroxyalkanoates) (PHA) have recently attracted increasing attention due to their biodegradability and high biocompatibility, which makes them suitable for the development of new prolong drug formulations. OBJECTIVE: This study was conducted to develop new prolong paclitaxel (PTX) formulation based on poly(3- hydroxybutyrate) (PHB) microparticles. METHOD: PHB microparticles loaded with antitumor cytostatic drug PTX were obtained by spray-drying method using Nano Spray Dryer B-90. The PTX release kinetics in vitro from PHB microparticles and their cytotoxity on murine hepatoma cell line MH-22a were studied. Microparticles antitumor activity in vivo was studied using intraperitoneally (i.p.) transplanted tumor models: murine Lewis lung carcinoma and xenografts of human breast cancer RMG1. RESULTS: Uniform PTX release from PHB-microparticles during 2 months was observed. PTX-loaded PHB microparticles have demonstrated a significant antitumor activity versus pure drug both in vitro in murine hepatoma cells and in vivo when administered i.p. to mice with murine Lewis lung carcinoma and xenografts of human breast cancer RMG1. CONCLUSION: The developed technique of PTX sustained delivery from PHB-microparticles has therapeutic potential as prolong anticancer drug formulation.