ABSTRACT
Objective: This study aims to develop a medical patch surface material featuring a microporous polyurethane (PU) membrane and to assess the material's properties and biological performance. The goal is to enhance the clinical applicability of pelvic floor repair patch materials. Methods: PU films with a microporous surface were prepared using PU prepolymer foaming technology. The films were produced by optimizing the PU prepolymer isocyanate index (R value) and the relative humidity (RH) of the foaming environment. The surface morphology of the PU microporous films was observed by scanning electron microscopy, and the chemical properties of the PU microporous films, including hydrophilicity, were analyzed using infrared spectroscopy, Raman spectroscopy, and water contact angle measurements. In vitro evaluations included testing the effects of PU microporous film extracts on the proliferation of L929 mouse fibroblasts and observing the adhesion and morphology of these fibroblasts. Additionally, the effect of the PU microporous films on RAW264.7 mouse macrophages was studied. Immune response and tissue regeneration were assessed in vivo using Sprague Dawley (SD) rats. Results: The PU films exhibited a well-defined and uniform microporous structure when the R value of PU prepolymer=1.5 and the foaming environment RH=70%. The chemical structure of the PU microporous films was not significantly altered compared to the PU films, with a significantly lower water contact angle ([55.7±1.5]° ) compared to PU films ([69.5±1.7]° ) and polypropylene (PP) ([ 104.3±2.5]°), indicating superior hydrophilicity. The extracts from PU microporous films demonstrated good in vitro biocompatibility, promoting the proliferation of L929 mouse fibroblasts. The surface morphology of the PU microporous films facilitated fibroblast adhesion and spreading. The films also inhibited the secretion of tumor necrosis factor-α (TNF-α) and interleukin (IL)-1ß by RAW264.7 macrophages while enhancing IL-10 and IL-4 secretion. Compared to 24 hours, after 72 hours of culture, the expression levels of TNF-α and IL-1ß were reduced in both the PU film and PU microporous film groups and were significantly lower than those in the PP film group (P<0.05), with the most notable decreases observed in the PU microporous film group. IL-10 and IL-4 levels increased significantly in the PU microporous film group, surpassing those in the PP film group (P<0.01), with the most pronounced increase in IL-4. The PU microporous film induced mild inflammation with no significant fibrous capsule formation in vivo. After 60 days of implantation, the film partially degraded, showing extensive collagen fiber growth and muscle formation in its central region. Conclusion: The PU microporous film exhibits good hydrophilicity and biocompatibility. Its surface morphology enhances cell adhesion, regulates the function of RAW264.7 macrophages, and promotes tissue repair, offering new insights for the design of pelvic floor repair and reconstruction patch materials.
Subject(s)
Fibroblasts , Polypropylenes , Polyurethanes , Rats, Sprague-Dawley , Polyurethanes/chemistry , Animals , Mice , Rats , Polypropylenes/chemistry , Fibroblasts/cytology , Biocompatible Materials/chemistry , Surgical Mesh , RAW 264.7 Cells , Surface Properties , Cell Line , Porosity , Materials Testing , Cell Proliferation/drug effects , Macrophages/cytologyABSTRACT
Scaffolds with multiphasic structures are considered to be superior for guided tissue regeneration. Two types of tilapia skin collagen gradient membranes (stepped gradient and linear gradient) with multiphasic structures were prepared by controlling the collagen concentrations and the freezing rates. The results revealed that collagen gradient membranes were more capable of guiding tissue regeneration compared to homogeneous membranes. These two gradient membranes featured a dense outer layer and a loose inner layer, with good mechanical properties as indicated by tensile strengths of more than 250 Kpa and porosities exceeding 85â¯%. Additionally, these membranes also showed good hydrophilicity and water absorption, with an inner layer contact angle of less than 91° and a water absorption ratio greater than 40 times. Furthermore, the multiphasic scaffolds were proved to be biocompatible by the acute toxicity assay, the intradermal irritation test and so on. Gradient membranes could effectively promote the adhesion and proliferation of fibroblasts and osteoblasts, through elevating the TGF-ß/Smad signaling pathway by TGF-ß and Smads, and activating the Wnt/ß-catenin signaling pathway by LRP5 and ß-catenin, similar to homogenous membranes. Therefore, collagen gradient membranes from tilapia skin show important application value in guiding tissue regeneration.
ABSTRACT
Bioglasses are solid materials consisted of sodium oxide, calcium oxide, silicon dioxide and phosphorus in various proportions and have used in bone tissue engineering. There have been ongoing efforts to improve the surface properties of bioglasses to increase biocompatibility and performance. The aim of the present study is to modify the bioglass surface with an amino acid mixture consisting of arginine, aspartic acid, phenylalanine, cysteine, histidine and lysine, to characterize the surface, and to evaluate the performance and biocompatibility in vitro and in vivo. The untreated bioglass, bioglass kept in simulated body fluid (SBF), and modified bioglass were used in further evaluation. After confirmation of the surface modification with FT-IR analyses and SEM analyses, MC3T3-E1 preosteoblasts adhesion on the surface was also revealed by SEM. The modified bioglass had significantly higher ALP activity in colorimetric measurement, rate of calcium accumulations in Alizarin red s staining, lower rate of cell death in Annexin-V/PI staining to determine apoptosis and necrosis. Having higher cell viability rate in MTT test and absence of genotoxicity in micronucleus test (OECD 487), the modified bioglass was further confirmed for biocompatibility in vitro. The results of the rat tibial defect model revealed that the all bioglass treatments had a significantly better bone healing score compared to the untreated negative control. However, the modified bioglass exhibited significantly better bone healing efforts especially during the first and the second months compared to the other bioglass treatment treatments. As a result, the amino acid surface modification of bioglasses improves the surface biocompatibility and osteogenic performance that makes the amino acid modified bioglass a better candidate for bone tissue engineering. RESEARCH HIGHLIGHTS: Bioglass surface modification with amino acids contributes to bioglass-tissue interaction with an improved cell attachment. Modified bioglass increases in vitro Alp activity and calcium accumulation, and also positively affects cell behavior by supporting cell adaptation. Bioglass exerts osteogenic potential in vivo especially during early bone healing.
ABSTRACT
Chitosan has established itself as a multifunctional and auspicious biomaterial within the domain of tissue engineering, presenting a decade of uninterrupted advancements and novel implementations. This article provides a comprehensive overview of the most recent developments in chitosan-based tissue engineering, focusing on significant progress made in the last ten years. An exploration is conducted of the various techniques utilized in the modification of chitosan and the production of scaffolds, with an analysis of their effects on cellular reactions and tissue regeneration. The investigation focuses on the integration of chitosan with other biomaterials and the addition of bioactive agents to improve their functionalities. Upon careful analysis of the in vitro and in vivo research, it becomes evident that chitosan effectively stimulates cell adhesion, proliferation, and differentiation. Furthermore, we offer valuable perspectives on the dynamic realm of chitosan-based approaches tailored to distinct tissue categories, including nerve, bone, cartilage, and skin. The review concludes with a discussion of prospective developments, with particular attention given to possible directions for additional study, translational implementations, and the utilization of chitosan to tackle existing obstacles in the field of tissue engineering. This extensive examination provides a significant amalgamation of the advancements achieved over the previous decade and directs scholars towards uncharted territories in chitosan-based tissue engineering.
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BACKGROUND: Assessing the biocompatibility of materials is crucial for ensuring the safety and well-being of patients by preventing undesirable, toxic, immune, or allergic reactions, and ensuring that materials remain functional over time without triggering adverse reactions. To ensure a comprehensive assessment, planning tests that carefully consider the intended application and potential exposure scenarios for selecting relevant assays, cell types, and testing parameters is essential. Moreover, characterizing the composition and properties of biomaterials allows for a more accurate understanding of test outcomes and the identification of factors contributing to cytotoxicity. Precise reporting of methodology and results facilitates research reproducibility and understanding of the findings by the scientific community, regulatory agencies, healthcare providers, and the general public. AIMS: This article aims to provide an overview of the key concepts associated with evaluating the biocompatibility of biomaterials while also offering practical guidance on cellular principles, testing methodologies, and biological assays that can support in the planning, execution, and reporting of biocompatibility testing.
ABSTRACT
Cerium oxide nanoparticles (CeNPs) have emerged as a potent therapeutic agent in the realm of wound healing, attributing their efficacy predominantly to their exceptional antioxidant properties. Mimicking the activity of endogenous antioxidant enzymes, CeNPs alleviate oxidative stress and curtail the generation of inflammatory mediators, thus expediting the wound healing process. Their application spans various disease models, showcasing therapeutic potential in treating inflammatory responses and infections, particularly in oxidative stress-induced chronic wounds such as diabetic ulcers, radiation-induced skin injuries, and psoriasis. Despite the promising advancements in laboratory studies, the clinical translation of CeNPs is challenged by several factors, including biocompatibility, toxicity, effective drug delivery, and the development of multifunctional compounds. Addressing these challenges necessitates advancements in CeNP synthesis and functionalization, novel nano delivery systems, and comprehensive bio effectiveness and safety evaluations. This paper reviews the progress of CeNPs in wound healing, highlighting their mechanisms, applications, challenges, and future perspectives in clinical therapeutics.
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Magnesium alloys, noted for their substantial mechanical strength and exceptional biocompatibility, are increasingly being considered for use in biodegradable implants. However, their rapid degradation and significant hydrogen release have limited their applications in orthopaedics. In this study, a novel Mg-RE-Sr alloy was created by friction stir processing to modify its microstructure and enhance its degradation performance. Through microstructural characterization, the friction stir processing effectively refined the grains, accelerated the re-dissolution of precipitates, and ensured a uniform distribution of these phases. The processed alloy demonstrated improved comprehensive properties, with an in vitro corrosion rate of approximately 0.4 mm/y and increases in ultimate tensile strength and elongation by 37 % and 166 %, respectively. Notably, in vivo experiments involving a rat subcutaneous implantation model revealed a slower degradation rate of 0.09 mm/y and a uniform degradation process, basically achieving the requirements for ideal performance in orthopaedic applications. The superior degradation characteristics were attributed to the synergistic effect of attenuated galvanic corrosion and the formation of a dense Y(OH)3/Y2O3 film induced by an exceptional microstructure with a highly solid-soluted matrix and uniformly refined precipitates. Meanwhile, the alloys exhibited excellent biocompatibility and did not cause undesirable inflammation or produce toxic degradation products. These improvements in biocompatibility and degradation characteristics indicate great promise for the use of this friction stir processed alloy in osteosynthesis systems in the clinical setting.
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The therapeutic approach to many solid tumors, including non-small cell lung cancer (NSCLC), is mainly based on the use of platinum-containing anticancer agents and is often characterized by acquired or intrinsic resistance to the drug. Therefore, the search for safer and more effective drugs is still an open challenge. Two organometallic ruthenium(II) cyclopentadienyl compounds [Ru(η5-C5H4CHO)(Me2bipy)(PPh3)]+ (RT150) and [Ru(η5-C5H4CH2OH)(Me2bipy) (PPh3)][CF3SO3] (RT151) were tested against a panel of cisplatin-resistant NSCLC cell lines and xenografts. They were more effective than cisplatin in inducing oxidative stress and DNA damage, affecting the cell cycle and causing apoptosis. Importantly, they were found to be inhibitors of drug efflux transporters. Due to this property, the compounds significantly increased the retention and cytotoxicity of cisplatin within NSCLC cells. Notably, they did not display high toxicity in vitro against non-transformed cells (red blood cells, fibroblasts, bronchial epithelial cells, cardiomyocytes, and endothelial cells). Both compounds induced vasorelaxation and reduced endothelial cell migration, suggesting potential anti-angiogenic properties. RT151 confirmed its efficacy against NSCLC xenografts resistant to cisplatin. Either alone or combined with low doses of cisplatin, RT151 showed a good biodistribution profile in the liver, kidney, spleen, lung, and tumor. Hematochemical analysis and post-mortem organ pathology confirmed the safety of the compound in vivo, also when combined with cisplatin. To sum up, we have confirmed the effectiveness of a novel class of drugs against cisplatin-resistant NSCLC. Additionally, they have a good biocompatibility and safety profile.
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Methotrexate (MTX) is a folic acid antagonist routinely used in cancer treatment, characterized by poor water solubility and low skin permeability. These issues could be mitigated by using drug delivery systems, such as functionalized gold nanoparticles (AuNPs), known for their versatility and unique properties. This study aimed to develop multi-shell AuNPs functionalized with MTX for the improvement of MTX antitumoral, antioxidant, and biocompatibility features. Stable phosphine-coated AuNPs were synthesized and functionalized with tailored polyethylene glycol (PEG) and short-branched polyethyleneimine (PEI) moieties, followed by MTX covalent binding. Physicochemical characterization by UV-vis and Fourier-transform infrared spectroscopy (FTIR) spectroscopy, dynamic light scattering (DLS), scanning transmission electron microscopy (STEM), and X-ray photoelectron spectroscopy (XPS) confirmed the synthesis at each step. The antioxidant activity of functionalized AuNPs was determined using DPPH radical scavenging assay, ferric ions' reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC) assays. Biocompatibility and cytotoxicity were assessed using MTT and LDH assays on HaCaT human keratinocytes and CAL27 squamous cell carcinoma. MTX functionalized AuNPs demonstrated enhanced antioxidant activity and a pronounced cytotoxic effect on the tumoral cells compared to their individual components, highlighting their potential for improving cancer therapy.
Subject(s)
Antioxidants , Gold , Metal Nanoparticles , Methotrexate , Methotrexate/pharmacology , Methotrexate/administration & dosage , Methotrexate/chemistry , Gold/chemistry , Humans , Metal Nanoparticles/chemistry , Antioxidants/pharmacology , Antioxidants/administration & dosage , Cell Line, Tumor , Polyethylene Glycols/chemistry , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Cell Survival/drug effects , Antineoplastic Agents/pharmacology , Antineoplastic Agents/administration & dosage , Polyethyleneimine/chemistry , HaCaT Cells , Keratinocytes/drug effectsABSTRACT
The interfaces between medical implants and living tissues are of great complexity because of the simultaneous occurrence of a wide variety of phenomena. The engineering of implant surfaces represents a crucial challenge in material science, but the further improvement of implant properties remains a critical task. It can be achieved through several processes. Among them, the production of specialized coatings based on carbon-based materials stands very promising. The use of carbon coatings allows one to simultaneously fine-tune tribological, mechanical, and chemical properties. Here, we review applications of nanostructured carbon coatings (nanodiamonds, carbon nanotubes, and graphene-related materials) for the improvement of the overall properties of medical implants. We are focusing on biological interactions, improved corrosion resistance, and overall mechanical properties, trying to provide a complete overview within the field.
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Ionic liquids (ILs) represent an exciting and promising solution for advancing drug delivery platforms. Their unique properties, including broad chemical diversity, adaptable structures, and exceptional thermal stability, make them ideal candidates for overcoming challenges in transdermal drug delivery. Despite encountering obstacles such as side reactions, impurity effects, biocompatibility concerns, and stability issues, ILs offer substantial potential in enhancing drug solubility, navigating physiological barriers, and improving particle stability. To propel the use of IL-based drug delivery in pharmaceutical innovation, it is imperative to devise new strategies and solvents that can amplify drug effectiveness, facilitate drug delivery to cells at the molecular level, and ensure compatibility with the human body. This review introduces innovative methods to effectively address the challenges associated with transdermal drug delivery, presenting progressive approaches to significantly improve the efficacy of this drug delivery system.
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This study investigates the impact of hydrophobic modification on the immunogenicity, cytotoxicity, and inflammatory response of Alaska pollock gelatin (ApGltn) microparticles (MPs). Gelatin, known for its inherent biocompatibility, was modified with decyl group (C10) to explore potential alterations in its interaction with the immune system. Immunogenicity was evaluated through the measurement of material-specific IgM and IgG responses, indicating no significant increase post-modification. Cytotoxicity against Caco-2 cell lines and NF-κB-mediated LPS-induced inflammation were also assessed, revealing no exacerbation by the modified MPs. Furthermore, C10 modification with different types of linkage such as secondary amine and amide structure did not influence immune reactivity. These findings suggest that C10 modification maintains the non-immunogenicity and biocompatibility of gelatin MPs, supporting their potential use in biomedical applications.
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Contact lenses have been instrumental in vision correction and are expected to be utilized in augmented reality (AR) displays through the integration of electronic and optical components. In optics, metasurfaces, an array of sub-wavelength nanostructures, have offered optical multifunctionality in an ultra-compact form factor, facilitating integration into various imaging, and display systems. However, transferring metasurfaces onto contact lenses remains challenging due to the non-biocompatible materials of extant imprinting methods and the structural instability caused by the swelling and shrinking of the wetted surface. Here, a biocompatible method is presented to transfer metasurfaces onto contact lenses using hyaluronic acid (HA) as a soft mold and to allow for holographic light projection. A high-efficiency metahologram is obtained with an all-metallic 3D meta-atom enhanced by the anisotropy of a rectangular structure, and a reflective background metal layer. A corrugated metal layer on the HA mold is supported with a SiO2 capping layer, to avoid unwanted wrinkles and to ensure structural stability when transferred to the surface of pliable and wettable contact lenses. Biocompatible method of transferring metasurfaces onto contact lenses promises the integration of diverse optical components, including holograms, lenses, gratings and more, to advance the visual experience for AR displays and human-computer interfaces.
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BACKGROUND AND OBJECTIVES: The dura mater is a barrier between the brain and the surrounding environment. Injuries to the dura can lead to serious complications, therefore, ensuring a hermetic closure of the dura is a primary task for a neurosurgeon. The aim of the study is to compare the effectiveness of applying the newly developed Viscoll®DURA collagen membrane (VDCM), with the commercially available Durepair (xenogeneic collagen) in animal model. METHODS: A dural tear model was utilized in rats with membrane implantation using an application method. The sample size consisted of 24 rats. Group I underwent VDCM implantation, while Group II underwent Durepair implantation. Results were evaluated at 30, 60, and 90 days. The study was assessed using MRI, histology, electron scanning microscopy, and immunohistochemistry. The obtained results underwent statistical analysis. RESULTS: In the clinical presentation there were no difference between groups. Histologically, Group 1 showed comparable results to Group 2. The integration process of the membrane statistically differed between the groups. In Group 1, neovascularization and tissue replacement showed better results than in Group 2. MRI differences were observed at later stages, with group 2 showing adhesion and brain deformation in the implantation area. CONCLUSION: Both membranes showed safety and compatibility. The collagen membrane produced under sterile conditions demonstrated better regeneration with minimal inflammatory reaction. The study suggests that VDCM exhibits biocompatibility comparable to Durepair, providing prospects for potential applications in neurosurgery.
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Carboxymethylated Cassia fistula gum (CCFG) and citric acid (CA) based wound healing film, (CCFG-CA) was developed using the solvent casting method. Glycerol was added as a plasticizing agent. The synthesized Carboxymethylated Cassia fistula gum cross-linked citric acid based hydrogel film (CCFG-CA) was evaluated morphologically, thermally, and structurally using FESEM, TGA, XRD and FTIR. Three essential oils (EO), rosemary (Rosmarinus officinalis), turmeric (Curcuma longa) and thuja (Thuja occidentalis L), known for antimicrobial and antioxidant activities, were loaded into the CCFG-CA film to develop essential oils loaded carboxymethylated Cassia fistula gum cross-linked citric acid based hydrogel film (CCFG-CA-EO). In vitro studies (MTT assay, disk diffusion assay, permeability tests and DPPH assay) confirm the biocompatibility, anti-oxidant and anti-microbial properties of the CCFG-CA-EO film. In vivo (wound healing studies on wistar rats and their histology) shows 99â¯% of wound healing and re-epithelialization in 14â¯days. Degradability (within 15â¯days), protein adsorption (12.05⯵g/mL) and contact angle determination (69.43°××⯱â¯0.48) tests confirmed the potential of CCFG-CA-EO as an effective wound-healing material.
ABSTRACT
Two-dimension graphene oxide (GO) nanosheets with high and low serum protein binding profiles (high/low hard-bound protein corona/HChigh/low) are used in this study as model materials and screening tools to investigate the underlying roles of the protein corona on nanomaterial toxicities in vivo. We proposed that the in vivo biocompatibility/nanotoxicity of GO is protein corona-dependent and host immunity-dependent. The hypothesis was tested by injecting HChigh/low GO nanosheets in immunocompetent ICR/CD1 and immunodeficient NOD-scid II2rγnull mice and performed histopathological and hematological evaluation studies on days 1 and 14 post-injection. HClow GO induced more severe acute lung injury compared to HChigh GO in both immunocompetent and immunodeficient mice, with the effect being particularly pronounced in immunocompetent animals. Additionally, HClow GO caused more significant liver injury in both types of mice, with immunodeficient mice being more susceptible to its hepatotoxic effects. Moreover, administration of HClow GO resulted in increased hematological toxicity and elevated levels of serum pro-inflammatory cytokines in immunocompromised and immunocompetent mice, respectively. Correlation studies were conducted to explore the impact of distinct protein corona compositions on resulting toxicities in both immunocompetent and immunodeficient mice. This facilitated the identification of consistent patterns, aligning with those observed in vitro, thus indicating a robust in vitro-in vivo correlation. This research will advance our comprehension of how hard corona proteins interact with immune cells, leading to toxicity, and will facilitate the development of improved immune-modulating nanomaterials for therapeutic purposes.
Subject(s)
Graphite , Mice, Inbred ICR , Nanostructures , Protein Corona , Animals , Graphite/chemistry , Graphite/toxicity , Mice , Protein Corona/chemistry , Protein Corona/immunology , Nanostructures/chemistry , Nanostructures/toxicity , Mice, SCID , Mice, Inbred NODABSTRACT
Microbial keratitis associated with contact lenses (CLs) wear remains a significant clinical concern. Antibiotic therapy is the current standard of care. However, the emergence of multidrug-resistant pathogens necessitates the investigation of alternative strategies. Antibiotic-free antimicrobial contact lenses (AFAMCLs) represent a promising approach in this regard. The effectiveness of CLs constructed with a variety of antibiotic-free antimicrobial strategies against microorganisms has been demonstrated. However, the impact of these antimicrobial strategies on CLs biocompatibility remains unclear. In the design and development of AFAMCLs, striking a balance between robust antimicrobial performance and optimal biocompatibility, including safety and wearing comfort, is a key issue. This review provides a comprehensive overview of recent advancements in AFAMCLs technology. The focus is on the antimicrobial efficacy and safety of various strategies employed in AFAMCLs construction. Furthermore, this review investigates the potential impact of these strategies on CLs parameters related to wearer comfort. This review aims to contribute to the continuous improvement of AFAMCLs and provide a reference for the trade-off between resistance to microorganisms and wearing comfort. In addition, it is hoped that this review can also provide a reference for the antimicrobial design of other medical devices.
ABSTRACT
The retention capacity of polymers is related to the development of systems that combine high surface-to-volume ratio with good handling and specific functionality. Biodegradability and biocompatibility are also key features for extending the field of applications to areas such as biomedicine. With this in mind, the aim of this work is to develop biodegradable, biocompatible, and highly functionalized porous films, that ensure suitable handling and a good surface-to-volume ratio. Polylactic acid (PLA) is applied as a polymer matrix to which a polycaprolactone with a star-shaped architecture (PCL-COOH) to ensure a high concentration of carboxylic end functionalities is added. The porous films are prepared using the phase inversion technique, which, as shown by Scanning Electron Microscopy (SEM) analysis, promotes good dispersion of the PCL-COOH domains. Absorption and release measurements performed with a positively charged model molecule show that the retention capacity and release rate can be tuned by changing the PCL-COOH concentration in the systems. Moreover, the adsorption properties for the formulation with the highest PCL-COOH content are also demonstrated with a real and widely used drug, namely doxorubicin. Finally, the bio- and hemocompatibility of the films, which are enzymatically degradable, are evaluated by using human keratinocytes and red blood cells, respectively.
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Cardiovascular diseases (CVDs) cause 30% of deaths each year, and in 2030, around 23.6 million people will die due to CVDs. The major challenge is to obtain molecules with minimal adverse reactions that can prevent and dissolve blood clots. In this context, fibrinolytic enzymes from diverse microorganism sources have been extensively investigated due to their potential to act directly and specifically on the fibrin clot, preventing side effects and performing potential thrombolytic effects. However, most researches focus on the purification and characterization of proteases, with little emphasis on the mechanism of action and pharmacological characteristics, including toxicity assays which are essential to assess safety and side effects. Therefore, this work aims to emphasize the importance of evaluations indicating the toxicological profile of fibrinolytic proteases through in vitro and in vivo tests. Both types of assays contribute as preclinical stage in drug development and are crucial for clinical applications. This scarcity creates arbitrary barriers to further studies. This work should further encourage the development of studies to ensure the safety and effectivity of fibrinolytic proteases.
Suggested pre-clinical trials aim to validate more specific methods for fibrinolytic enzymes;Current toxicity standards can be adapted to better assess the profile of fibrinolytic enzymes;The class of fibrinolytic enzymes must be carefully evaluated according to the method of application.
ABSTRACT
Carbon dots (CDs) have rapidly emerged as a new family of carbon-based nanomaterials since their initial discovery two decades ago. Numerous appealing properties, such as precursor and synthesis process flexibility, tunable photoluminescence, and good biocompatibility, have enabled their widespread applications in sensing, catalysis, energy, and biomedical fields. As the field expands, notable efforts have recently focused on mechanistically elucidating the structural formation and optical behavior of CDs. However, the absence of "clean" CDs presents a major obstacle to achieving a solid understanding of these aspects. Often, the claimed CDs are, in fact, a mixture of small molecules, oligomers, nano-sized aggregates, or even microparticles. Such coexistence of impurities markedly impacts the physicochemical properties of resulting CD-based mixtures, hampering the resolution of key mechanistic questions. Here, we aim to address this fundamental shortcoming of the field, going beyond the customary focus of the existing reviews that predominantly cover synthesis, optical performance, and application prospects. We begin with an overview of CD synthesis and then thoroughly examine the purification methods, including filtration, dialysis, electrophoresis, and chromatography. The insights provided here will guide the researchers towards obtaining high-quality CDs, employing proper combinations of available tools, and ultimately paving the way for more demanding applications.