Bacterial Cellulose-Based Materials: A Perspective on Cardiovascular Tissue Engineering Applications

Bacterial cellulose: Is it really a promising biomedical material?

Bacterial cellulose (BC) is currently considered a promising biomaterial due to its specific structure and properties. However, despite extensive research, questions about its fundamental properties, especially biocompatibility, remain. Thus, the purpose of this review is to analyze the results of in vivo trials from different areas of biomedicine, including wound healing, tissue engineering, drug delivery, and biomedical implants. The primary question guiding our review was "Why is bacterial cellulose still not used in clinical practice?" Analysis of the literature has shown that the results of in vivo studies often contradict each other. For example, BC caused and did not cause an immune response in an equal number of reviewed articles. Its efficacy in pure form generally does not differ significantly from that of materials already on the market. Conversely, BC may prove to be a valuable material in the long term, not because of its efficacy, but rather because of its affordability and ease of use. Additionally, challenges associated with immune reactions, long-term biocompatibility, and the necessity for standardized experimental protocols must be addressed. We expect that this review will encourage a more thoughtful investigation of BC to bring it into practical medicine.

Gradually-frozen aligned bacterial nanocellulose membranes loaded with gallic acid exhibit enhanced mechanical and dual antithrombotic-antimicrobial properties

Bacterial nanocellulose (BNC) is a versatile natural polymer with unique morphological properties. However, its susceptibility to biofouling limits its utility in healthcare. To address this challenge, this study explores the incorporation of gallic acid, a phenolic acid with potent antimicrobial and antithrombotic properties, into BNC membranes. Additionally, a novel drying method termed gradual freezing is introduced, resulting in a directionally-aligned BNC membrane with enhanced mechanical integrity and high porosity. Using glycerol as a solvent and plasticizer, gallic acid was loaded into air-dried BNC (AD-BNC), freeze-dried BNC (FD-BNC), and gradually-frozen BNC (GF-BNC) membranes. Successful drug-loading into FD-BNC and GF-BNC significantly increased the elasticity of the films, however mechanical testing indicated that GF-BNC and its gallic acid/glycerol loaded counterpart (GF-GG-BNC) achieved overall optimal mechanical strength and elasticity. These samples were selected for further antifouling testing. Antibacterial assays demonstrated the practical efficacy of GF-GG-BNC in inhibiting the proliferation and biofilm formation of E. coli and S. aureus, while favorable antithrombotic behaviour prevented clot formation and red blood cell adhesion on the material's surface when compared to GF-BNC membranes. These findings highlight the potential of GF-GG-BNC as a multifunctional biomaterial for the prevention of biofouling in biomedical applications.

Structure, production and application of spider silks

Spider silk plays a pivotal role in the diverse physiological activities of spiders, with its protein components exhibiting remarkable mechanical properties and biocompatibility. Spider silk proteins exhibit a high degree of repetitiveness, primarily constructed through the recurring arrangement of amino acid motifs, including (A)n, (GA)n, (GGX)n, and (GPGXX)n sequences. These repetitive sequences endow spider silk with different material properties. Recombinant spider silk proteins are produced through heterologous expression systems, and then spun into nanofibers using artificial spinning technology. These fibers have broad potential applications in the biomedical field, such as tissue engineering scaffolds, drug delivery carriers, sutures, and other biomaterials. However, enhancing the yield and performance of recombinant spider silk proteins, while facilitating large-scale production, continues to pose a significant challenge in the current landscape.

Harnessing the potential of tissue engineering to target male infertility: Insights into testicular regeneration

Male infertility is among one of the most challenging health concerns in the world. Traditional therapeutic interventions such as semen and testicular tissue cryopreservation aim to restore or preserve male fertility. However, these methods are subject to limitations that impact their efficacy and are infeasible in cases such as patients who cannot produce mature sperm due to genetic or pathological disorders. Moreover, with the number of cases of prepubertal boys who must undergo gonadotoxic treatments rising, alternatives have been sought for fertility preservation to enhance reproductive rates in vitro and in vivo. Tissue engineering is a promising area that can address aspects that current therapies may not fully encompass through the creation of bioartificial testicular structures or 3D culture systems that allow the establishment of the essential conditions for sperm production. This study aims to first give a brief overview of stem cell therapy in treating male infertility and then go more in-depth regarding the novel methods and procedures based on tissue engineering that have the potential to offer new treatments for infertility caused by testicular disorders and defects.

The role of Collagen Tissue Scaffolds in 3D Endometrial-like Culture Systems: Important Contributions to Cell Invasion and Cell Topography

Considering the similarity between the invasion processes of cancer cells and embryo implantation, three-dimensional culture models used to study cancer cell invasion can also be applied to embryo implantation studies. In our study, endometrial epithelial cell line (RL95-2) and spheroid-forming trophoblast-like choriocarcinoma cell line (JAR) were cultured on three different biocompatible tissue scaffolds: bacterial cellulose, collagen foam and collagen fibre. These scaffolds are frequently used in cancer cell metastasis and invasion studies, A three-dimensional endometrium-like culture system was established to quantitatively investigate the role of E-cadherin, N-cadherin, Vimentin, α-smooth muscle actin and Syndecan-1 proteins in the type 1 epithelial mesenchymal transition mechanism observed during the invasion step of the implantation process. Based on the findings from the three-dimensional cell culture, the bacterial cellulose scaffold promoted the proliferation of RL95-2 cells and delayed JAR spheroid formation. The collagen foam scaffold favored the proliferation of RL95-2 cells and accelerated JAR spheroid formation. The collagen fibre scaffold is important for supporting cell topography and, when combined with collagen foam, may offer a potential solution for investigating 3D endometrium-like culture systems. Immunocytochemical and immunofluorescence analyses showed that scaffolds modulate the invasion process by affecting the expression of epithelial mesenchymal transition proteins in cells. The findings suggest that different tissue scaffolds can produce varying effects in endometrium-like culture systems, and combinations of these materials may yield more effective results in future studies. This research represents a critical step in studying cell behavior in 3D culture systems and elucidates the mechanism of endometrial invasion.

Advances in polysaccharide-based materials for biomedical and pharmaceutical applications: A comprehensive review

Polysaccharides, the most abundant biopolymers in nature, have attracted the attention of researchers and clinicians due to its practicality in biomedical and pharmaceutical sciences. These biomaterials have high bioavailability and play structural and functional roles in living organisms. Polysaccharides are classified into several groups based on their origin, including plant polysaccharides and marine polysaccharides (like chitosan, hyaluronic acid, dextran, alginates, etc.) with specific applications. These biopolymers possess unique physicochemical (such as surface functional groups, solubility, and stability), mechanical (like mechanical strength and tensile), and biomedical (such as antioxidant activity, biocompatibility, biodegradability, renewability, and non-immunogenicity) characteristics which have made them excellent platforms for a wide variety of biomedical and pharmaceutical applications. Ease of extraction and different preparation approaches are mentioned as other potential properties of polysaccharides that further improved their practicality in biomedical sciences. They have high drug/bioactive encapsulation capacity and sustained/controlled release manner in in vivo microenvironments. The anti-inflammatory and immunomodulation, stimuli-responsive drug/bioactive release, and passive and active drug/bioactive delivery are considered the potential features of these biopolymers in pharmaceutical sciences. Polysaccharides have indicated practical applications in biomedical sciences, including biosensors, tissue engineering, implantation, wound healing, vascular grafting, and vaccines. This review highlights the advances of polysaccharide-based materials in biomedical and pharmaceutical sciences.

Bacterial nanocelluloses as sustainable biomaterials for advanced wound healing and dressings

Wound healing remains a significant clinical challenge, calling for innovative approaches to expedite the recovery process and improve patient outcomes. Bacterial nanocelluloses (BNCs) have emerged as a promising solution in the field of wound healing and dressings due to their unique properties such as high crystallinity, mechanical strength, high purity, porosity, high water absorption capacity, biodegradability, biocompatibility, sustainability, and flexibility. BNC-based materials can be applied for the treatment of different types of wounds, from second-degree burns to skin tears, biopsy sites, and diabetic and ischemic wounds. BNC-based dressings have exceptional mechanical properties such as flexibility and strength, which ensure proper wound coverage and protection. The renewable nature, eco-friendly production process, longer lifespan, and potential for biodegradability of BNCs make them a more sustainable alternative to conventional wound care materials. This review aims to provide a detailed overview on the application of BNC-based composites for wound healing and dressings via highlighting their ability as a carrier for delivery of different types of antimicrobial compounds as well as their direct effect on the healing process. Besides, it mentions some of the in vivo and clinical studies using BNC-based dressings and describes challenges related to the application of these materials as well as their future directions.

Enhanced bacterial cellulose production by Komagataeibacter species and Hibiscus sabdariffa herbal tea

This study proposed Hibiscus sabdariffa as a novel substrate for BC production with Komagataeibacter species and their consortia. K. intermedius is found as the most efficient producer (5.98 g/L BC, 3.56 × 10-2 g-1 h-1 productivity rate) following K. maltaceti (4.44 g/L BC, 2.64 × 10-2 g-1 h-1 productivity rate) and K. nataicola (3.67 g/L BC, 2.18 × 10-2 g-1 h-1 productivity rate). Whereas agitation increased BC production with K. nataicola (1.22-fold, 4.49 g/L BC), K. maltaceti (1.24-fold, 5.52 g/L BC) and K. intermedius (1.27-fold, 7.63 g/L BC), irregular shaped BC was obtained. This could be a novel result as Komagataeibacter consortia increased BC production by 1.17-2.01-fold compared to monocultures resulting as 8.11 g/L BC through the co-cultivation of K. maltaceti-K. intermedius. Maximum increase was found to be 1.75-fold (1.79-fold WHC), occurring with monoculture of K. maltaceti, while 1.94-fold (1.26-fold WHC) with K. maltaceti-K. intermedius consortium when H. sabdariffa-based media compared Hestrin-Schramm media. Based on these results, this could be a novel result as H. sabdariffa-based media may replace the use of HS media in BC production by means of a bioactive content-rich plant and obtaining 3-D ultrafine porous structure with high thermal resistant (∼460-500 °C) BC with mono and co-cultivation of Komagataeibacter species to be used in industrial area.

Performance of magnetic nanocomposite based on xanthan gum-grafted-poly(acrylamide) crosslinked by borax for the effective elimination of amoxicillin from aquatic environments

This study evaluated the effectiveness of using nanocomposite (NCs) of xanthan gum grafted polyacrylamide crosslinked Borax - iron oxide nanoparticle (XG-g-pAAm-CL-Borax-IONP) to remove the amoxicillin antibiotic (AMX) from an aquatic environment. To confirm the structural characteristics of the prepared XG-g-pAAm-CL-Borax-IONP NCs, unique characterization methods (XRD, FT-IR, FE-SEM, EDX, BET, TGA, Zeta, and VSM) were used. Adsorption experimental setups were performed with the influence of solution pH (4-9), the effect of adsorbent dose (0.003-0.02 g), the effect of contact time (5-45 min), and the effect of initial AMX concentration (50-400 mg/L) to achieve the most efficient adsorption conditions. Based on the Freundlich isotherm model, XG-g-pAAm-CL-Borax-IONP NCs provided the maximum AMX adsorption capacity of 1183.639 mg/g. This research on adsorption kinetics also established that the pseudo-second-order model (R2 = 0.991) is outstanding compatibility with the experimental results. AMX adsorption on the NCs may occur through intermolecular hydrogen bonding, diffusion, and trapping into the polymer network. Even after five cycles, these NCs still displayed the best performance. Based on these results, XG-g-pAAm-CL-Borax-IONP NCs may be a viable material for the purification of AMX from contaminated water.

An L-shaped relationship between dietary vitamin K and atherosclerotic cardiovascular disease

BACKGROUND AND AIMS

Few studies link vitamin K intake with incident atherosclerotic cardiovascular disease (ASCVD), and the specific mechanism remains uncertain. We aimed to evaluate the relationship between dietary vitamin K and ASCVD.

METHODS

This study used cross-sectional data from people over 20 years old who took part in the National Health and Nutrition Examination Survey (NHANES) between 2013 and 2018. Vitamin K intake was assessed using a 24-h dietary review. The Patient Medical Conditions Questionnaire was used to assess ASCVD. The stability of the outcomes was evaluated using cubic spline models with restricted parameters and logistic regression, while subgroup analyses were also performed.

RESULTS

There were 14,465 participants, with 9.78% (1415/14,465) who diagnosed with ASCVD. Compared with individuals with lower vitamin K intake Q1 (≤39.0 ug/day), the adjusted OR values for dietary vitamin K intake and ASCVD in Q2 (39.1-70.8 ug/day), Q3 (70.9-131.0 mg/day), and Q4 (≥131.1 ug/day) were 0.88 (95% CI: 0.74-1.04, p = 0.134), 0.77(95% CI: 0.65-0.93, p = 0.005), and 0.78 (95% CI: 0.65-0.95, p = 0.013), respectively. The association between dietary vitamin K intake and ASCVD showed an L-shaped curve (nonlinear, p = 0.006). The OR for ASCVD in participants with vitamin K intake <127.1ug/day was 0.996 (95% CI: 0.993-0.998, p = 0.002).

CONCLUSIONS

The relationship between dietary vitamin K intake and ASCVD was L-shaped curve in US adults, the inflection point was roughly 127.1 ug/day.

Effect of the ex situ physical and in situ chemical modification of bacterial nanocellulose on mechanical properties in the context of its potential applications in heart valve design

Bacterial nanocellulose (BNC) is a promising material for heart valve prostheses. However, its low strength properties limit its applicability in cardiovascular surgery. To overcome these limitations, the mechanical properties of BNC can be improved through modifications. The aim of the research was to investigate the extent to which the mechanical properties of BNC can be altered by modifying its structure during its production and after synthesis. The study presents the results of various analyses, including tensile tests, nanoindentation tests, X-ray diffraction (XRD) tests, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy, conducted on BNC chemically modified in situ with hyaluronic acid (BNC/HA) and physically modified ex situ through a dehydration/rehydration process (BNC 25DR, BNC105DR, BNC FDR and BNC/HA 25DR, BNC/HA 105DR, BNC/HA FDR). The results demonstrate that both chemical and physical modifications can effectively shape the mechanical properties of BNC. These modifications induce changes in the crystalline structure, pore size and distribution, and residual stresses of BNC. Results show the effect of the crystalline structure of BNC on its mechanical properties. There is correlation between hardness and Young's modulus and Iα/Iβ index for BNC/HA and between creep rate of BNC/HA, and Young's modulus for BNC vs Iα/Iβ index.

Shaping the Future of Cardiovascular Disease by 3D Printing Applications in Stent Technology and its Clinical Outcomes

Cardiovascular disease (CVD) is a leading cause of death worldwide. In recent years, 3D printing technology has ushered in a new era of innovation in cardiovascular medicine. 3D printing in CVD management encompasses various aspects, from patient-specific models and preoperative planning to customized medical devices and novel therapeutic approaches. In-stent technology, 3D printing has revolutionized the design and fabrication of intravascular stents, offering tailored solutions for complex anatomies and individualized patient needs. The advantages of 3D-printed stents, such as improved biocompatibility, enhanced mechanical properties, and reduced risk of in-stent restenosis. Moreover, the clinical trials and case studies that shed light on the potential of 3D printing technology to improve patient outcomes and revolutionize the field has been comprehensively discussed. Furthermore, regulatory considerations, and challenges in implementing 3D-printed stents in clinical practice are also addressed, underscoring the need for standardization and quality assurance to ensure patient safety and device reliability. This review highlights a comprehensive resource for clinicians, researchers, and policymakers seeking to harness the full potential of 3D printing technology in the fight against CVD.

Revolutionizing biomedicine: advancements, applications, and prospects of nanocomposite macromolecular carbohydrate-based hydrogel biomaterials: a review

Nanocomposite hydrogel biomaterials represent an exciting Frontier in biomedicine, offering solutions to longstanding challenges. These hydrogels are derived from various biopolymers, including fibrin, silk fibroin, collagen, keratin, gelatin, chitosan, hyaluronic acid, alginate, carrageenan, and cellulose. While these biopolymers possess inherent biocompatibility and renewability, they often suffer from poor mechanical properties and rapid degradation. Researchers have integrated biopolymers such as cellulose, starch, and chitosan into hydrogel matrices to overcome these limitations, resulting in nanocomposite hydrogels. These innovative materials exhibit enhanced mechanical strength, improved biocompatibility, and the ability to finely tune drug release profiles. The marriage of nanotechnology and hydrogel chemistry empowers precise control over these materials' physical and chemical properties, making them ideal for tissue engineering, drug delivery, wound healing, and biosensing applications. Recent advancements in the design, fabrication, and characterization of biopolymer-based nanocomposite hydrogels have showcased their potential to transform biomedicine. Researchers are employing strategic approaches for integrating biopolymer nanoparticles, exploring how nanoparticle properties impact hydrogel performance, and utilizing various characterization techniques to evaluate structure and functionality. Moreover, the diverse biomedical applications of these nanocomposite hydrogels hold promise for improving patient outcomes and addressing unmet clinical needs.

Production of Bacterial Exopolysaccharides: Xanthan and Bacterial Cellulose

Recently, degradable biopolymers have become increasingly important as potential environmentally friendly biomaterials, providing a wide range of applications in various fields. Bacterial exopolysaccharides (EPSs) are biomacromolecules, which due to their unique properties have found applications in biomedicine, foodstuff, textiles, cosmetics, petroleum, pharmaceuticals, nanoelectronics, and environmental remediation. One of the important commercial polysaccharides produced on an industrial scale is xanthan. In recent years, the range of its application has expanded significantly. Bacterial cellulose (BC) is another unique EPS with a rapidly increasing range of applications. Due to the great prospects for their practical application, the development of their highly efficient production remains an important task. The present review summarizes the strategies for the cost-effective production of such important biomacromolecules as xanthan and BC and demonstrates for the first time common approaches to their efficient production and to obtaining new functional materials for a wide range of applications, including wound healing, drug delivery, tissue engineering, environmental remediation, nanoelectronics, and 3D bioprinting. In the end, we discuss present limitations of xanthan and BC production and the line of future research.

Advances in drug delivery applications of modified bacterial cellulose-based materials

Bacterial cellulose (BC) is generated by certain species of bacteria and comprises polysaccharides with unique physical, chemical, and mechanical characteristics. Due to its outstanding biocompatibility, high purity, excellent mechanical strength, high water absorption, and highly porous structure, bacterial cellulose has been recently investigated for biomedical application. However, the pure form of bacterial cellulose is hardly used as a biomedical material due to some of its inherent shortcomings. To extend its applications in drug delivery, modifications of native bacterial cellulose are widely used to improve its properties. Usually, bacterial cellulose modifications can be carried out by physical, chemical, and biological methods. In this review, a brief introduction to bacterial cellulose and its production and fabrication is first given, followed by up-to-date and in-depth discussions of modification. Finally, we focus on the potential applications of bacterial cellulose as a drug delivery system.