Photochemically Induced Crosslinking of Tarsal Collagen as a Treatment for Eyelid Laxity: Assessing Potentiality in Animal Tissue.

PURPOSE: An experimental study to demonstrate in animal eyelids that the controlled exposure of excised tarsal plate to ultraviolet-A radiation can induce a rigidification effect due to photochemical crosslinking of the constitutive collagen. METHODS: Excised strips of sheep tarsus were irradiated with ultraviolet-A rays (wavelength 365 nm) at low and high irradiances, in the presence of riboflavin as a photosensitizer, using radiation sources available for corneal collagen crosslinking procedure. The tensile strength and Young's modulus (stiffness) of irradiated and control samples were measured in a mechanical tester and analyzed statistically. Histologic examination of the specimens was carried out to evaluate the effect of radiation on the meibomian glands and collagen organization. RESULTS: Mechanical evaluation showed that irradiation induced both stiffening and strengthening of the tarsal plate specimens, and this effect was enhanced at the higher levels of irradiance. The changes in mechanical properties can be attributed to a process of photochemically induced crosslinking of tarsal collagen. Histology revealed no changes in the meibomian glands or in the fibrous collagen system of the tarsus. CONCLUSIONS: These findings indicate that irradiation of tarsal collagen leading to tissue stiffening could be a safe procedure for treating lax eyelid conditions in human patients.

Cellular and Molecular Mechanisms Underlying Non-Pharmaceutical Ischemic Stroke Therapy in Aged Subjects.

The incidence of ischemic stroke in humans increases exponentially above 70 years both in men and women. Comorbidities like diabetes, arterial hypertension or co-morbidity factors such as hypercholesterolemia, obesity and body fat distribution as well as fat-rich diet and physical inactivity are common in elderly persons and are associated with higher risk of stroke, increased mortality and disability. Obesity could represent a state of chronic inflammation that can be prevented to some extent by non-pharmaceutical interventions such as calorie restriction and hypothermia. Indeed, recent results suggest that H2S-induced hypothermia in aged, overweight rats could have a higher probability of success in treating stroke as compared to other monotherapies, by reducing post-stroke brain inflammation. Likewise, it was recently reported that weight reduction prior to stroke, in aged, overweight rats induced by caloric restriction, led to an early re-gain of weight and a significant improvement in recovery of complex sensorimotor skills, cutaneous sensitivity, or spatial memory. CONCLUSION: animal models of stroke done in young animals ignore age-associated comorbidities and may explain, at least in part, the unsuccessful bench-to-bedside translation of neuroprotective strategies for ischemic stroke in aged subjects.

Dental implant placement with bone augmentation in a patient who received intravenous bisphosphonate treatment for osteoporosis.

Intravenous (IV) administration of bisphosphonates has been considered an absolute contraindication for placement of dental implants, because of the increased risk of bisphosphonate-related osteonecrosis of the jaw (BRONJ). However, the evidence regarding this association originates from patients being treated for various forms of metastatic cancer. In the case reported here, a patient received a dental implant while undergoing IV treatment with zoledronic acid for osteoporosis. The authors discuss the current evidence regarding the risks of dental procedures in patients receiving IV bisphosphonates for this indication. They also evaluate important risk factors and the decision-making pathway in such cases. On the basis of existing evidence, receipt of a single IV infusion of zoledronic acid for the treatment of osteoporosis does not appear to be an absolute contraindication to implant placement.

Collagen-Coated Hyperelastic Bone Promotes Osteoblast Adhesion and Proliferation.

Successfully reconstructing bone and restoring its dynamic function represents a significant challenge for medicine. Critical size defects (CSDs), resulting from trauma, tumor removal, or degenerative conditions, do not naturally heal and often require complex bone grafting. However, these grafts carry risks, such as tissue rejection, infections, and surgical site damage, necessitating the development of alternative treatments. Three-dimensional and four-dimensional printed synthetic biomaterials represent a viable alternative, as they carry low production costs and are highly reproducible. Hyperelastic bone (HB), a biocompatible synthetic polymer consisting of 90% hydroxyapatite and 10% poly(lactic-co-glycolic acid, PLGA), was examined for its potential to support cell adhesion, migration, and proliferation. Specifically, we seeded collagen-coated HB with MG-63 human osteosarcoma cells. Our analysis revealed robust cell adhesion and proliferation over 7 days in vitro, with cells forming uniform monolayers on the external surface of the scaffold. However, no cells were present on the core of the fibers. The cells expressed bone differentiation markers on days 3 and 5. By day 7, the scaffold began to degrade, developing microscopic fissures and fragmentation. In summary, collagen-coated HB scaffolds support cell adhesion and proliferation but exhibit reduced structural support after 7 days in culture. Nevertheless, the intricate 3D architecture holds promise for cellular migration, vascularization, and early osteogenesis.

The Use of Hydrogels for the Treatment of Bone Osteosarcoma via Localized Drug-Delivery and Tissue Regeneration: A Narrative Review.

Osteosarcoma is a malignant tumor of bone that leads to poor mortality and morbidity. Management of this cancer through conventional methods involves invasive treatment options that place patients at an increased risk of adverse events. The use of hydrogels to target osteosarcoma has shown promising results both in vitro and in vivo to eradicate tumor cells while promoting bone regeneration. The loading of hydrogels with chemotherapeutic drugs provides a route for site-specific targeted therapy for osteosarcoma. Current studies demonstrate tumor regression in vivo and lysis of tumor cells in vitro when exposed to doped hydrogel scaffolds. Additionally, novel stimuli-responsive hydrogels are able to react with the tissue microenvironment to facilitate the controlled release of anti-tumor drugs and with biomechanical properties that can be modulated. This narrative review of the current literature discusses both in vitro and in vivo studies of different hydrogels, including stimuli-responsive, designed to treat bone osteosarcoma. Future applications to address patient treatment for this bone cancer are also discussed.

Medication-related osteonecrosis of the jaw: A disease of significant importance for older patients.

BACKGROUND: Medication-related osteonecrosis of the jaw (MRONJ) is clinically defined as a non-healing jawbone ulcerative-necrotic lesion appearing after dental therapy or minor trauma in patients treated previously with anti-resorptive, anti-angiogenic or immunomodulators. Older patients with osteoporosis and cancer receive these pharmacological agents regularly. As these patients are long-term survivors, efficient treatment is of paramount importance for their quality of life. METHODS: Literature searches via PubMed were conducted to identify relevant MRONJ studies. Basic information on MRONJ classification, clinical features, and pathosphysiology is presented herein as well as various clinical studies dealing with MRONJ in patients with osteoporosis and cancer. Lastly, we discuss current managment of patients and new trends in treatment of MRONJ. RESULTS: Although close follow-up and local hygiene have been advocated by some authors, severe forms of MRONJ are not responsive to conservative therapy. At present, there is no "gold standard" therapy for this condition. However, as the physiopathological basis of MRONJ is represented by the anti-angiogenic action of various pharmacological agents, new methods to increase and promote local angiogenesis and vascularization have recently been successfully tested in vitro, limited preclinical studies, and in a pilot clinical study. CONCLUSIONS: It appears that the best method implies application on the lesion of endothelial progenitor cells as well as pro-angiogenic factors such as Vascular Endothelial Growth Factor (VEGF) and other related molecules. More recently, scaffolds in which these factors have been incorporated have shown positive results in limited trials. However, these studies must be replicated to include a large number of cases before any official therapeutic protocol is adopted.

Local delivery of hydrogel encapsulated vascular endothelial growth factor for the prevention of medication-related osteonecrosis of the jaw.

The anti-angiogenic effects of bisphosphonates have been hypothesized as one of the major etiologic factors in the development of medication-related osteonecrosis of the jaw (MRONJ), a severe debilitating condition with limited treatment options. This study evaluated the potential of a gelatine-hyaluronic acid hydrogel loaded with the angiogenic growth factor, vascular endothelial growth factor (VEGF), as a local delivery system to aid in maintaining vascularization in a bisphosphonate-treated (Zoledronic Acid) rodent maxillary extraction defect. Healing was assessed four weeks after implantation of the VEGF-hydrogel into extraction sockets. Gross examination and histological assessment showed that total osteonecrosis and inflammatory infiltrate was significantly reduced in the presence of VEGF. Also, total vascularity and specifically neovascularization, was significantly improved in animals that received VEGF hydrogel. Gene expression of vascular, inflammatory and bone specific markers within the defect area were also significantly altered in the presence of VEGF. Furthermore, plasma cytokine levels were assessed to determine the systemic effect of locally delivered VEGF and showed similar outcomes. In conclusion, the use of locally delivered VEGF within healing extraction sockets assists bone healing and prevents MRONJ via a pro-angiogenic and immunomodulatory mechanism.

Vascular Tissue Engineering: Advanced Techniques and Gene Editing in Stem Cells for Graft Generation.

The common occurrence of cardiovascular diseases and the lack of proper autologous tissues prompt and promote the pressing development of tissue-engineered vascular grafts (TEVGs). Current progress on scaffold production, genetically modified cells, and use of nanotechnology-based monitoring has considerably improved the long-term patency of engineered tissue grafts. However, challenges abound in the autologous materials and manipulation of genes and cells for tissue engineering. This review overviews current development in TEVGs and discusses recent improvements in scaffolding techniques and the efficiency of gene-editing tools and their ability to fill the existing gaps in stem cell and regenerative therapies. Current advances in three-dimensional printing approaches for fabrication of engineered tissues are also reviewed together with specific biomaterials for vascular tissues. In addition, the natural and synthetic polymers that hold increasing significance for vascular tissue engineering are highlighted. Both animal models and nanotechnology-based monitoring are proposed for preclinical evaluation of engineered grafts in view of their historical significance in tissue engineering. The ultimate success of tissue regeneration, which is yet to be fully realized, depends on the optimal performance of culture systems, biomaterial constructs, and stem cells in a suitable artificial physiological environment.

Ageing as a risk factor for cerebral ischemia: Underlying mechanisms and therapy in animal models and in the clinic.

Age is the only one non-modifiable risk of cerebral ischemia. Advances in stroke medicine and behavioral adaptation to stroke risk factors and comorbidities was successful in decreasing stroke incidence and increasing the number of stroke survivors in western societies. Comorbidities aggravates the outcome after cerebral ischemia. However, due to the increased in number of elderly, the incidence of stroke has increased again paralleled by an increase in the number of stroke survivors, many with severe disabilities, that has led to an increased economic and social burden in society. Animal models of stroke often ignore age and comorbidities frequently associated with senescence. This might explain why drugs working nicely in animal models fail to show efficacy in stroke survivors. Since stroke afflicts mostly the elderly comorbid patients, it is highly desirable to test the efficacy of stroke therapies in an appropriate animal stroke model. Therefore, in this review, we make parallels between animal models of stroke und clinical data and summarize the impact of ageing and age-related comorbidities on stroke outcome.

Long-term treatment with spermidine increases health span of middle-aged Sprague-Dawley male rats.

Let alone calorie restriction, life span extension in higher organisms has proven to be difficult to achieve using simple drugs. Previous studies have shown that the polyamine spermidine increased the maximum life span in C. elegans and the median life span in mice. However, younger subjects (< 40 years of age) are infrequently prescribed nor self-medicating with antiaging drugs. Therefore, in the present study, we aimed at assessing the effect of long-term treatment with spermidine given in the drinking water on behavioral performance and longevity of male, middle-aged Sprague-Dawley rats. We report that spermidine given in the drinking water did not extend neither the median nor the maximum life span of the middle-aged male Sprague-Dawley rats. However, spermidine treatment had a beneficial effect on the body weight and the kidney tubules, liver, and heart morphology. Behaviorally, spermidine led to a reduction in anxiety and an increase in curiosity, as assessed by exploratory behavior. Moreover, long-term treatment with spermidine enhanced autophagy in the brain and led to a diminished expression of the inflammatory markers, Tgfb, CD11b, Fcgr1, Stat1, CR3, and GFAP mRNAs in several cortical region and hippocampus of the treated rats suggesting that one beneficial effect of the long-term treatment with spermidine is an attenuated proinflammatory state in the aged brain. Our results suggest that long-term treatment with spermidine increases health span of middle-aged rats by attenuating neuroinflammation and improving anxiety and exploratory behavior.

Dietary habits, lifestyle factors and neurodegenerative diseases.

Worldwide stroke is increasing in parallel with modernization, changes in lifestyle, and the growing elderly population. Our review is focused on the link between diet, as part of 'modern lifestyle', and health in the context of genetic predisposition of individuals to 'unhealthy' metabolic pathway activity. It is concluded that lifestyle including high sugar diets, alcohol and tobacco addiction or high fat diets as well as ageing, brain injury, oxidative stress and neuroinflammation, negatively influence the onset, severity and duration of neurodegenerative diseases. Fortunately, there are several healthy dietary components such as polyunsaturated fatty acids and the anti-oxidants curcumin, resveratrol, blueberry polyphenols, sulphoraphane, salvionic acid as well as caloric restriction and physical activity, which may counteract ageing and associated neurodegenerative diseases via increased autophagy or increased neurogenesis in the adult brain.

Extracellular Alpha-Synuclein Promotes a Neuroinhibitory Secretory Phenotype in Astrocytes.

Multiple system atrophy (MSA) and dementia with Lewy bodies (DLB) are α-synucleinopathies that exhibit widespread astrogliosis as a component of the neuroinflammatory response. Munc18, a protein critical to vesicle exocytosis, was previously found to strongly mark morphologically activated astrocytes in brain tissue of MSA patients. Immunofluorescence of MSA, DLB and normal brain tissue sections was combined with cell culture and co-culture experiments to investigate the relationship between extracellular α-synuclein and the transition to a secretory astrocyte phenotype. Increased Munc18-positive vesicles were resolved in activated astrocytes in MSA and DLB tissue compared to controls, and they were also significantly upregulated in the human 1321N1 astrocytoma cell line upon treatment with α-synuclein, with parallel increases in GFAP expression and IL-6 secretion. In co-culture experiments, rat primary astrocytes pretreated with α-synuclein inhibited the growth of neurites of co-cultured primary rat neurons and upregulated chondroitin sulphate proteoglycan. Taken together, these results indicate that the secretory machinery is significantly upregulated in the astrocyte response to extracellular α-synuclein and may participate in the release of neuroinhibitory and proinflammatory factors in α-synucleinopathies.

The Cyclin-Dependent Kinase 5 Inhibitor Peptide Inhibits Herpes Simplex Virus Type 1 Replication.

In order to evaluate the influence of CDK5 inhibitory peptide (CIP) on Human alphaherpesvirus 1 (HSV-1) replication, we constructed two recombinant adeno-associated-virus 2 (rAAV2) vectors encoding CIP fused with cyan-fluorescent-protein (CFP), with or without nuclear localization signal. A third vector encoding non-fused CIP and CFP was also constructed. HeLa and HEK 293T cells were infected with the rAAV-CIP vectors at multiplicity of infection (MOI) of 5000, in the absence or presence of a recombinant HSV-1 that encodes a yellow-fluorescent-protein (rHSV48Y; MOI = 1). Cells co-infected with rHSV48Y and rAAV vectors that did not express the CIP gene (rAAV-CFP-Neo) served as controls. At 24 h after infection, the effect of CIP on rHSV48Y replication was assessed by PCR, qRT-PCR, Western-blot, flow-cytometry, epifluorescence and confocal microscopy. We show that in cultures co-infected with rAAV-CFP-Neo, 27% of the CFP-positive cells present rHSV48Y replication compartments. By contrast, in cultures co-infected with CIP-encoding rAAV2 vectors and rHSV48Y only 6-20% of the cells positive for CIP showed rHSV48Y replication compartments, depending on the CIP variant. Flow-cytometry showed that less than 40% of the rHSV48Y/rAAV-CIP, and more than 75% of rHSV48Y/rAAV-CFP-Neo co-infected cells were positive for both transgene products. The microscopy and flow-cytometry data support the hypothesis that CIP is inhibiting HSV-1 replication.

Cellular and molecular events underlying the dysregulated response of the aged brain to stroke: a mini-review.

BACKGROUND: Age-related brain injuries, including stroke, are a major cause of physical and mental disabilities. OBJECTIVE: Therefore, studying the basic mechanism underlying functional recovery after brain stroke in aged subjects is of considerable clinical interest. METHODS: This review summarizes the effects of age on recovery after stroke in an animal model, with emphasis on the underlying cellular mechanisms. RESULTS: Data from our laboratory and elsewhere indicate that, behaviorally, aged rats were more severely impaired by stroke than young rats, and they also showed diminished functional recovery. Infarct volume did not differ significantly between young and aged animals, but critical differences were apparent in the cytological response to stroke, most notably an age-related acceleration in the development of the glial scar. Early infarct in older rats is associated with premature accumulation of BrdU-positive microglia and astrocytes, persistence of activated oligodendrocytes, a high incidence of neuronal degeneration and accelerated apoptosis. In aged rats, neuroepithelial-positive cells were rapidly incorporated into the glial scar, but these neuroepithelial-like cells did not make a significant contribution to neurogenesis in the infarcted cortex in young or aged animals. The response of plasticity-associated proteins like MAP1B, was delayed in aged rats. Tissue recovery was further delayed by an age-related increase in the amount of the neurotoxic C-terminal fragment of the beta-amyloid precursor protein (A-beta) at 2 weeks poststroke. CONCLUSION: The available evidence indicates that the aged brain has the capability to mount a cytoproliferative response to injury, but the timing of the cellular and genetic response to cerebral insult is dysregulated in aged animals, thereby further compromising functional recovery. Elucidating the molecular basis for this phenomenon in the aging brain could yield novel approaches to neurorestoration in the elderly.

Combining electrospinning and cell sheet technology for the development of a multiscale tissue engineered ligament construct (TELC).

Ligament tissue rupture is a common sport injury. Although current treatment modalities can achieve appropriate reconstruction of the damaged ligament, they present significant drawbacks, mostly related to reduced tissue availability and pain associated with tissue harvesting. Stem cell based tissue regeneration combined with electrospun scaffolds represents a novel treatment method for torn ligaments. In this study, a low fiber density polycaprolactone (PCL) electrospun mesh and sheep mesenchymal stem cells (sMSCs) were used to develop tissue engineered ligament construct (TELC) in vitro. The assembly of the TELC was based on the spontaneous capacity of the cells to organize themselves into a cell sheet once seeded onto the electrospun mesh. The cell sheet matured over 4 weeks and strongly integrated with the low fiber density electrospun mesh which was subsequently processed into a ligament-like bundle and braided with two other bundles to develop the final construct. Live/dead assay revealed that the handling of the construct through the various phases of assembly did not cause significant difference in viability compared to the control. Mechanical evaluation demonstrated that the incorporation of the cell sheet into the braided construct resulted in significantly modifying the mechanical behavior. A stress/displacement J-curve was observed for the TELC that was similar to native ligament, whereas this particular feature was not observed in the non-cellularized specimens. The regenerative potential of the TELC was evaluated ectopically in immunocompromized rats, compared to non cellularized electrospun fiber mesh and this demonstrated that the TELC was well colonized by host cells and that a significant remodelling of the implanted construct was observed. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 399-409, 2018.

3D printing strategies for peripheral nerve regeneration.

After many decades of biomaterials research for peripheral nerve regeneration, a clinical product (the nerve guide), is emerging as a proven alternative for relatively short injury gaps. This review identifies aspects where 3D printing can assist in improving long-distance nerve guide regeneration strategies. These include (1) 3D printing of the customizable nerve guides, (2) fabrication of scaffolds that fill nerve guides, (3) 3D bioprinting of cells within a matrix/bioink into the nerve guide lumen and the (4) establishment of growth factor gradients along the length a nerve guide. The improving resolution of 3D printing technologies will be an important factor for peripheral nerve regeneration, as fascicular-like guiding structures provide one path to improved nerve guidance. The capability of 3D printing to manufacture complex structures from patient data based on existing medical imaging technologies is an exciting aspect that could eventually be applied to treating peripheral nerve injury. Ultimately, the goal of 3D printing in peripheral nerve regeneration is the automated fabrication, potentially customized for the patient, of structures within the nerve guide that significantly outperform the nerve autograft over large gap injuries.

Stem cell therapies in preclinical models of stroke. Is the aged brain microenvironment refractory to cell therapy?

Stroke is a devastating disease demanding vigorous search for new therapies. Initial enthusiasm to stimulate restorative processes in the ischemic brain by means of cell-based therapies has meanwhile converted into a more balanced view recognizing impediments that may be related to unfavorable age-associated environments. Recent results using a variety of drug, cell therapy or combination thereof suggest that, (i) treatment with Granulocyte-Colony Stimulating Factor (G-CSF) in aged rats has primarily a beneficial effect on functional outcome most likely via supportive cellular processes such as neurogenesis; (ii) the combination therapy, G-CSF with mesenchymal cells (G-CSF+BM-MSC or G-CSF+BM-MNC) did not further improve behavioral indices, neurogenesis or infarct volume as compared to G-CSF alone in aged animals; (iii) better results with regard to integration of transplanted cells in the aged rat environment have been obtained using iPS of human origin; (iv) mesenchymal cells may be used as drug carriers for the aged post-stroke brains. CONCLUSION: While the middle aged brain does not seem to impair drug and cell therapies, in a real clinical practice involving older post-stroke patients, successful regenerative therapies would have to be carried out for a much longer time.

Caloric restriction stabilizes body weight and accelerates behavioral recovery in aged rats after focal ischemia.

Obesity and hyperinsulinemia are risk factors for stroke. We tested the hypothesis that caloric restriction, which reduces the incidence of age-related obesity and metabolic syndrome, may represent an efficient and cost-effective strategy for preventing stroke and its devastating consequences. To this end, we placed aged, obese Sprague-Dawley aged rats on a calorie-restricted diet for 8 weeks prior to the experimental infarction. Stroke in this animal model caused a progressive decrease in weight that reached a minimum at day 6 for the young rats, and at day 10 for the aged, ad libitum-fed rats. However, in aged animals that were calorie-restricted prior to stroke, body weight did not decrease after stroke, but we noted accelerated body weight gain shortly thereafter starting at day 5 poststroke. Moreover, calorie-restricted aged animals showed improved behavioral recovery in tasks requiring complex sensorimotor skills, or in tasks requiring cutaneous sensitivity and sensorimotor integration or spatial memory. Likewise, calorie-restricted aged rats showed significant poststroke increases in serum glucose, insulin, and IGF1 levels, as well as CR-specific changes in the expression of gene transcripts involved in glycogen metabolism, IGF signaling, apoptosis, arteriogenesis, and hypoxia. In conclusion, our study shows that recovery from stroke is enhanced in aged rats by a dietary regimen that reduces body weight prior to infarct.

The effect of bisphosphonates on the endothelial differentiation of mesenchymal stem cells.

The contribution of the local stem cell niche to providing an adequate vascular framework during healing cannot be overemphasized. Bisphosphonates (BPs) are known to have a direct effect on the local vasculature, but their effect on progenitor cell differentiation is unknown. This in vitro study evaluated the effect(s) of various BPs on the differentiation of human placental mesenchymal stem cells (pMSCs) along the endothelial lineage and their subsequent functional and morphogenic capabilities. pMSC multipotency was confirmed by successful differentiation into cells of both the osteogenic and endothelial lineages, as demonstrated by positive Alizarin Red S staining and Ac-LDL uptake. pMSC differentiation in the presence of non-cytotoxic BP concentrations showed that nitrogen containing BPs had a significant inhibitory effect on cell migration and endothelial marker gene expression, as well as compromised endothelial differentiation as demonstrated using von Willebrand factor immunofluorescence staining and tube formation assay. This in vitro study demonstrated that at non-cytotoxic levels, nitrogen-containing BPs inhibit differentiation of pMSCs into cells of an endothelial lineage and affect the downstream functional capability of these cells supporting a multi-modal effect of BPs on angiogenesis as pathogenic mechanism contributing to bone healing disorders such as bisphosphonate related osteonecrosis of the jaws (BRONJ).

Artistic Skills Recovery and Compensation in Visual Artists after Stroke.

BACKGROUND: Art is a characteristic of mankind, which requires superior central nervous processing and integration of motor functions with visual information. At the present time, a significant amount of information related to neurobiological basis of artistic creation has been derived from neuro-radiological cognitive studies, which have revealed that subsequent to tissue destruction, the artists continue to create art. The current study aims to review the most important cases of visual artists with stroke and to discuss artistic skills recovery and compensation as well as artistic style after stroke. METHODS: The role of various central nervous system regions in artistic creation was reviewed on the basis of previously published functional studies. Our PubMed search (1995-2015) has identified 10 famous artists with right cerebral stroke as well as 5 with left cerebral stroke who survived and continued to create art after stroke. As the artists included in this review lived at various times during the twentieth century and in different countries, clinical information related to their case was limited. However, it appears that artistic skills recovery and compensation appear within days after stroke. Some of the artists would subsequently change their artistic style. All these elements have been evaluated within the context of specific clinical cases. CONCLUSION: The poststroke artistic skills recovery and compensation with development of a new style or the opposite, regaining the previous prestroke style, represents a significant element of clinical importance in medical rehabilitation as well as neuroesthetics, which requires further evaluation. At the present time, the molecular mechanisms of artistic creation are poorly understood, and more standardized clinical and experimental studies are needed.