Local intramyocardial delivery of bioglass with alginate hydrogels for post-infarct myocardial regeneration

Bioactive Glass in Tissue Regeneration: Unveiling Recent Advances in Regenerative Strategies and Applications

Bioactive glass (BG) is a class of biocompatible, biodegradable, multifunctional inorganic glass materials, which is successfully used for orthopedic and dental applications, with several products already approved for clinical use. Apart from exhibiting osteogenic properties, BG is also known to be angiogenic and antibacterial. Recently, BG's role in immunomodulation has been gradually revealed. While the therapeutic effect of BG is mostly reported in the context of bone and skin-related regeneration, its application in regenerating other tissues/organs, such as muscle, cartilage, and gastrointestinal tissue, has also been explored recently. The strategies of applying BG have also expanded from powder or cement form to more advanced strategies such as fabrication of composite polymer-BG scaffold, 3D printing of BG-loaded scaffold, and BG-induced extracellular vesicle production. This review presents a concise overview of the recent applications of BG in regenerative medicine. Various regenerative strategies of BG will be first introduced. Next, the applications of BG in regenerating various tissues/organs, such as bone, cartilage, muscle, tendon, skin, and gastrointestinal tissue, will be discussed. Finally, summarizing clinical applications of BG for tissue regeneration will conclude, and outline future challenges and directions for the clinical translation of BG.

In vivo evaluation by oral administration of chitosan combined with bioactive glass against cadmium-induced toxicity in rats

Bioactive glass and chitosan are biomaterials widely used for orthopedic applications, notably as bone grafts. Although these biomaterials show promising therapeutic properties, no research has yet examined their potential for oral administration in soft tissue protection, particularly against metal toxicity. The aim of our study was to evaluate the potential of chitosan from cuttlefish (CHS) bone combined with bioactive glass (BG) against Cadmium-induced toxicity in rats. Cadmium (Cd), a heavy metal that accumulates in tissues, causes various disorders. Experiments were carried out on rats intoxicated acutely by oral administration of Cd (20 mg/kg body weight) and/or concomitantly with oral administration of CHS/BG (100 mg/kg body weight) for 7 days. Using pathophysiological and biochemical tests, we evaluated the detoxifying effect of orally administered CHS/BG against Cd toxicity. Our results showed, for the first time, a significant detoxifying effect of CHS/BG against Cd-induced toxicity in rats. Treatment with CHS/BG protected rats against the harmful effects of Cd by reducing lipid peroxidation levels and enhancing antioxidant enzyme activities. In addition, it helped restore phosphocalcic balance and protect liver, kidney and brain function. Remarkably, it also reduced Cd levels in the liver, kidneys and brain, as well as in the bones of rats. These results show that oral administration of CHS/BG has a strong therapeutic potential on tissues through detoxification of cadmium-exposed rats.

Soft yet mechanically robust injectable alginate hydrogels with processing versatility based on alginate/hydroxyapatite hybridization

The salient gelling feature of alginate via forming the egg-box structure with calcium ions has received extensive interests for different applications. Owing to the interfacial incompatibility of rigid inorganic solids with soft polymers, the requirement of overall stereocomplexation with calcium released from uniformly distributed solids in alginate remains a challenge. In this study, a novel alginate-incorporated calcium source was proposed to tackle the intractable dispersion for the preparation of injectable alginate hydrogels. Calcium phosphate synthesis in alginate solution yielded CaP-alginate hybrids as a calcium source. The physicochemical characterization confirmed the CaP-alginate hybrid was a nano-scale alginate-hydroxyapatite complex. The colloidally stable CaP-alginate hybrids were uniformly dispersed in alginate solutions even under centrifugation. The calcium-induced gelling of the CaP-alginate hybrids-loaded alginate solutions formed soft yet tough hydrogels including transparent sheets and knittable threads, confirming the homogeneous gelation of the hydrogel. The gelation time, injectability and mechanical properties of the hydrogels could be adjusted by changing preparation parameters. The prepared hydrogels showed uniform porous structure, excellent swelling, wetting properties and cytocompatibility, showing a great potential for applications in different fields. The present strategy with organic/inorganic hybridization could be exemplarily followed in the future development of functional hydrogels especially associated with the interface integration.

Injectable hydrogel-based combination therapy for myocardial infarction: a systematic review and Meta-analysis of preclinical trials

INTRODUCTION

This study evaluates the effectiveness of a combined regimen involving injectable hydrogels for the treatment of experimental myocardial infarction.

PATIENT CONCERNS

Myocardial infarction is an acute illness that negatively affects quality of life and increases mortality rates. Experimental models of myocardial infarction can aid in disease research by allowing for the development of therapies that effectively manage disease progression and promote tissue repair.

DIAGNOSIS

Experimental animal models of myocardial infarction were established using the ligation method on the anterior descending branch of the left coronary artery (LAD).

INTERVENTIONS

The efficacy of intracardiac injection of hydrogels, combined with cells, drugs, cytokines, extracellular vesicles, or nucleic acid therapies, was evaluated to assess the functional and morphological improvements in the post-infarction heart achieved through the combined hydrogel regimen.

OUTCOMES

A literature review was conducted using PubMed, Web of Science, Scopus, and Cochrane databases. A total of 83 papers, including studies on 1332 experimental animals (rats, mice, rabbits, sheep, and pigs), were included in the meta-analysis based on the inclusion and exclusion criteria. The overall effect size observed in the group receiving combined hydrogel therapy, compared to the group receiving hydrogel treatment alone, resulted in an ejection fraction (EF) improvement of 8.87% [95% confidence interval (CI): 7.53, 10.21] and a fractional shortening (FS) improvement of 6.31% [95% CI: 5.94, 6.67] in rat models, while in mice models, the improvements were 16.45% [95% CI: 11.29, 21.61] for EF and 5.68% [95% CI: 5.15, 6.22] for FS. The most significant improvements in EF (rats: MD = 9.63% [95% CI: 4.02, 15.23]; mice: MD = 23.93% [95% CI: 17.52, 30.84]) and FS (rats: MD = 8.55% [95% CI: 2.54, 14.56]; mice: MD = 5.68% [95% CI: 5.15, 6.22]) were observed when extracellular vesicle therapy was used. Although there have been significant results in large animal experiments, the number of studies conducted in this area is limited.

CONCLUSION

The present study demonstrates that combining hydrogel with other therapies effectively improves heart function and morphology. Further preclinical research using large animal models is necessary for additional study and validation.

Bioactive Glass and Silica Particles for Skeletal and Cardiac Muscle Tissue Regeneration

When skeletal and cardiac tissues are damaged, surgical approaches are not always successful and tissue regeneration approaches are investigated. Reports in the literature indicate that silica nanoparticles and bioactive glasses (BGs), including silicate bioactive glasses (e.g., 45S5 BG), phosphate glass fibers, boron-doped mesoporous BGs, borosilicate glasses, and aluminoborates, are promising for repairing skeletal muscle tissue. Silica nanoparticles and BGs have been combined with polymers to obtain aligned nanofibers and to maintain controlled delivery of nanoparticles for skeletal muscle repair. The literature indicates that cardiac muscle regeneration can be also triggered by the ionic products of BGs. This was observed to be due to the release of vascular endothelial growth factor and other growth factors from cardiomyocytes, which regulate endothelial cells to form capillary structures (angiogenesis). Specific studies, including both in vitro and in vivo approaches, are reviewed in this article. The analysis of the literature indicates that although the research field is still very limited, BGs are showing great promise for muscle tissue engineering and further research in the field should be carried out to expand our basic knowledge on the application of BGs in muscle (skeletal and cardiac) tissue regeneration. Impact statement This review highlights the potential of silica particles and bioactive glasses (BGs) for skeletal and cardiac tissue regeneration. These biomaterials create scaffolds triggering muscle cell differentiation. Ionic products from BGs stimulate growth factors, supporting angiogenesis in cardiac tissue repair. Further research is required to expand our know-how on silica particles and BGs in muscle tissue engineering.

Oral Release Kinetics, Biodistribution, and Excretion of Dopants from Barium-Containing Bioactive Glass in Rats

Background: Inorganic biomaterials are biologically active and are used as implants and drug delivery system. They have therapeutically active elements present in their framework that are released in the physiological milieu. Release of these dopants above the supraphysiological limit may produce adverse effects and physicochemical interactions with the loaded drugs. Therefore, this necessitates evaluating the in vivo release kinetics, biodistribution, and excretion profiles of dopants from barium-doped bioglass (BaBG) that has potential anti-inflammatory, antiulcer, and regenerative properties. Methods: In vitro leaching of Ca, Si, and Ba from BaBG was analyzed in simulated body fluid. Release kinetics post single-dose oral administration (1, 5, and 10 mg/kg) was performed in rats. Blood was collected at different time points, and pharmacokinetic parameters of released elements were calculated. The routes of excretion and biodistribution in major organs were evaluated using ICP-MS. Results: Elements were released after the oral administration of BaBG into the plasma. They showed dose-dependent release kinetics and mean residence time. Cmax was observed at 24 h for all elements, followed by a downhill fall. There was also a dose-dependent increase in the volume of distribution, and the clearance of dopants was mostly through feces. Ba and Si were biodistributed significantly in the liver, spleen, and kidneys. However, by the end of day 7, there was a leveling-off effect observed for all elements. Conclusion: All of the dopants exhibited a dose-dependent increase in release kinetics and biodistribution in vital organs. This study will help in dose optimization and understanding of various physicochemical and pharmacokinetic interactions when BaBG is used for future pharmacological studies.

Modulation of 3D Bioprintability in Polysaccharide Bioink by Bioglass Nanoparticles and Multiple Metal Ions for Tissue Engineering

BACKGROUND

Bioglasses are used in applications related to bone rehabilitation and repair. The mechanical and bioactive properties of polysaccharides like alginate and agarose can be modulated or improved using bioglass nanoparticles. Further essential metal ions used as crosslinker have the potential to supplement cultured cells for better growth and proliferation.

METHOD

In this study, the alginate bioink is modulated for fabrication of tissue engineering scaffolds by extrusion-based 3D bioprinting using agarose, bioglass nanoparticles and combination of essential trace elements such as iron, zinc, and copper. Homogeneous bioink was obtained by in situ mixing and bioprinting of its components with twin screw extruder (TSE) based 3D bioprinting, and then distribution of metal ions was induced through post-printing diffusion of metal ions in the printed scaffolds. The mechanical and 3d bioprinting properties, microscopic structure, biocompatibility of the crosslinked alginate/agarose hydrogels were analyzed for different concentrations of bioglass. The adipose derived mesenchymal stem cells (ADMSC) and osteoblast cells (MC3T3) were used to evaluate this hydrogel's biological performances.

RESULTS

The porosity of hydrogels significantly improves with the incorporation of the bioglass. More bioglass concentration results in improved mechanical (compressive, dynamic, and cyclic) and 3D bioprinting properties. Cell growth and extracellular matrix are also enhanced with bioglass concentration.

CONCLUSION

For bioprinting of the bioinks, the advanced TSE head was attached to 3D bioprinter and in situ fabrication of cell encapsulated scaffold was obtained with optimized composition considering minimal effects on cell damage. Fabricated bioinks demonstrate a biocompatible and noncytotoxic scaffold for culturing MC3T3 and ADMSC, while bioglass controls the cellular behaviors such as cell growth and extracellular matrix formation.

Incorporation of Controlled Release Systems Improves the Functionality of Biodegradable 3D Printed Cardiovascular Implants

New horizons in cardiovascular research are opened by using 3D printing for biodegradable implants. This additive manufacturing approach allows the design and fabrication of complex structures according to the patient's imaging data in an accurate, reproducible, cost-effective, and quick manner. Acellular cardiovascular implants produced from biodegradable materials have the potential to provide enough support for in situ tissue regeneration while gradually being replaced by neo-autologous tissue. Subsequently, they have the potential to prevent long-term complications. In this Review, we discuss the current status of 3D printing applications in the development of biodegradable cardiovascular implants with a focus on design, biomaterial selection, fabrication methods, and advantages of implantable controlled release systems. Moreover, we delve into the intricate challenges that accompany the clinical translation of these groundbreaking innovations, presenting a glimpse of potential solutions poised to enable the realization of these technologies in the realm of cardiovascular medicine.

Advanced Bioactive Glasses: The Newest Achievements and Breakthroughs in the Area

Bioactive glasses (BGs) are especially useful materials in soft and bone tissue engineering and even in dentistry. They can be the solution to many medical problems, and they have a huge role in the healing processes of bone fractures. Interestingly, they can also promote skin regeneration and wound healing. Bioactive glasses are able to attach to the bone tissues and form an apatite layer which further initiates the biomineralization process. The formed intermediate apatite layer makes a connection between the hard tissue and the bioactive glass material which results in faster healing without any complications or side effects. This review paper summarizes the most recent advancement in the preparation of diverse types of BGs, such as silicate-, borate- and phosphate-based bioactive glasses. We discuss their physical, chemical, and mechanical properties detailing how they affect their biological performances. In order to get a deeper insight into the state-of-the-art in this area, we also consider their medical applications, such as bone regeneration, wound care, and dental/bone implant coatings.

The Utilisation of Hydrogels for iPSC-Cardiomyocyte Research

Cardiac fibroblasts' (FBs) and cardiomyocytes' (CMs) behaviour and morphology are influenced by their environment such as remodelling of the myocardium, thus highlighting the importance of biomaterial substrates in cell culture. Biomaterials have emerged as important tools for the development of physiological models, due to the range of adaptable properties of these materials, such as degradability and biocompatibility. Biomaterial hydrogels can act as alternative substrates for cellular studies, which have been particularly key to the progression of the cardiovascular field. This review will focus on the role of hydrogels in cardiac research, specifically the use of natural and synthetic biomaterials such as hyaluronic acid, polydimethylsiloxane and polyethylene glycol for culturing induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). The ability to fine-tune mechanical properties such as stiffness and the versatility of biomaterials is assessed, alongside applications of hydrogels with iPSC-CMs. Natural hydrogels often display higher biocompatibility with iPSC-CMs but often degrade quicker, whereas synthetic hydrogels can be modified to facilitate cell attachment and decrease degradation rates. iPSC-CM structure and electrophysiology can be assessed on natural and synthetic hydrogels, often resolving issues such as immaturity of iPSC-CMs. Biomaterial hydrogels can thus provide a more physiological model of the cardiac extracellular matrix compared to traditional 2D models, with the cardiac field expansively utilising hydrogels to recapitulate disease conditions such as stiffness, encourage alignment of iPSC-CMs and facilitate further model development such as engineered heart tissues (EHTs).

Effects of Bioactive Glasses (BGs) on Exosome Production and Secretion: A Critical Review

There is an increasing trend toward the application of bioactive glasses in different areas of biomedicine, including tissue engineering and oncology. The reason for this increase is mostly attributed to the inherent properties of BGs, such as excellent biocompatibility, and the ease of tailoring their properties by changing, for example, the chemical composition. Previous experiments have demonstrated that the interactions between BGs and their ionic dissolution products, and mammalian cells, can affect and change cellular behaviors, and thereby govern the performance of living tissues. However, limited research exists on their critical role in the production and secretion of extracellular vesicles (EVs) such as exosomes. Exosomes are nanosized membrane vesicles that carry various therapeutic cargoes such as DNA, RNA, proteins, and lipids, and thereby can govern cell-cell communication and subsequent tissue responses. The use of exosomes is currently considered a cell-free approach in tissue engineering strategies, due to their positive roles in accelerating wound healing. On the other hand, exosomes are known as key players in cancer biology (e.g., progression and metastasis), due to their capability to carry bioactive molecules between tumor cells and normal cells. Recent studies have demonstrated that the biological performance of BGs, including their proangiogenic activity, is accomplished with the help of exosomes. Indeed, therapeutic cargos (e.g., proteins) produced in BG-treated cells are transferred by a specific subset of exosomes toward target cells and tissues, and lead to a biological phenomenon. On the other hand, BGs are suitable delivery vehicles that can be utilized for the targeted delivery of exosomes to cells and tissues of interest. Therefore, it seems necessary to have a deeper understanding of the potential effects of BGs in the production of exosomes in cells that are involved in tissue repair and regeneration (mostly mesenchymal stem cells), as well as in those that play roles in cancer progression (e.g., cancer stem cells). This review aims to present an updated report on this critical issue, to provide a roadmap for future research in the fields of tissue engineering and regenerative medicine.

Interaction of Ceramic Implant Materials with Immune System

The immuno-compatibility of implant materials is a key issue for both initial and long-term implant integration. Ceramic implants have several advantages that make them highly promising for long-term medical solutions. These beneficial characteristics include such things as the material availability, possibility to manufacture various shapes and surface structures, osteo-inductivity and osteo-conductivity, low level of corrosion and general biocompatibility. The immuno-compatibility of an implant essentially depends on the interaction with local resident immune cells and, first of all, macrophages. However, in the case of ceramics, these interactions are insufficiently understood and require intensive experimental examinations. Our review summarizes the state of the art in variants of ceramic implants: mechanical properties, different chemical modifications of the basic material, surface structures and modifications, implant shapes and porosity. We collected the available information about the interaction of ceramics with the immune system and highlighted the studies that reported ceramic-specific local or systemic effects on the immune system. We disclosed the gaps in knowledge and outlined the perspectives for the identification to ceramic-specific interactions with the immune system using advanced quantitative technologies. We discussed the approaches for ceramic implant modification and pointed out the need for data integration using mathematic modelling of the multiple ceramic implant characteristics and their contribution for long-term implant bio- and immuno-compatibility.

Role of Biomaterials in Cardiac Repair and Regeneration: Therapeutic Intervention for Myocardial Infarction

Heart failure or myocardial infarction (MI) is one of the world's leading causes of death. Post MI, the heart can develop pathological conditions such as ischemia, inflammation, fibrosis, and left ventricular dysfunction. However, current surgical approaches are sufficient for enhancing myocardial perfusion but are unable to reverse the pathological changes. Tissue engineering and regenerative medicine approaches have shown promising effects in the repair and replacement of injured cardiomyocytes. Additionally, biomaterial scaffolds with or without stem cells are established to provide an effective environment for cardiac regeneration. Excipients loaded with growth factors, cytokines, oligonucleotides, and exosomes are found to help in such cardiac eventualities by promoting angiogenesis, cardiomyocyte proliferation, and reducing fibrosis, inflammation, and apoptosis. Injectable hydrogels, nanocarriers, cardiac patches, and vascular grafts are some excipients that can help the self-renewal in the damaged heart but are not understood well yet, in the context of used biomaterials. This review focuses on the use of various biomaterial-based approaches for the regeneration and repair of cardiac tissue postoccurrence of MI. It also discusses the outlines of cardiac remodeling and current therapeutic approaches after myocardial infarction, which are translationally important with respect to used biomaterials. It provides comprehensive details of the biomaterial-based regenerative approaches, which are currently the focus of the research for cardiac repair and regeneration and can provide a broad outline for further improvements.

Multifarious applications of bioactive glasses in soft tissue engineering

Tissue engineering (TE), a new paradigm in regenerative medicine, repairs and restores the diseased or damaged tissues and eliminates drawbacks associated with autografts and allografts. In this context, many biomaterials have been developed for regenerating tissues and are considered revolutionary in TE due to their flexibility, biocompatibility, and biodegradability. One such well-documented biomaterial is bioactive glasses (BGs), known for their osteoconductive and osteogenic potential and their abundant orthopedic and dental clinical applications. However, in the last few decades, the soft tissue regenerative potential of BGs has demonstrated great promise. Therefore, this review comprehensively covers the biological application of BGs in the repair and regeneration of tissues outside the skeleton system. BGs promote neovascularization, which is crucial to encourage host tissue integration with the implanted construct, making them suitable biomaterial scaffolds for TE. Moreover, they heal acute and chronic wounds and also have been reported to restore the injured superficial intestinal mucosa, aiding in gastroduodenal regeneration. In addition, BGs promote regeneration of the tissues with minimal renewal capacity like the heart and lungs. Besides, the peripheral nerve and musculoskeletal reparative properties of BGs are also reported. These results show promising soft tissue regenerative potential of BGs under preclinical settings without posing significant adverse effects. Albeit, there is limited bench-to-bedside clinical translation of elucidative research on BGs as they require rigorous pharmacological evaluations using standardized animal models for assessing biomolecular downstream pathways.

Therapeutic Acellular Scaffolds for Limiting Left Ventricular Remodelling-Current Status and Future Directions

Myocardial infarction (MI) is one of the leading causes of heart-related deaths worldwide. Following MI, the hypoxic microenvironment triggers apoptosis, disrupts the extracellular matrix and forms a non-functional scar that leads towards adverse left ventricular (LV) remodelling. If left untreated this eventually leads to heart failure. Besides extensive advancement in medical therapy, complete functional recovery is never accomplished, as the heart possesses limited regenerative ability. In recent decades, the focus has shifted towards tissue engineering and regenerative strategies that provide an attractive option to improve cardiac regeneration, limit adverse LV remodelling and restore function in an infarcted heart. Acellular scaffolds possess attractive features that have made them a promising therapeutic candidate. Their application in infarcted areas has been shown to improve LV remodelling and enhance functional recovery in post-MI hearts. This review will summarise the updates on acellular scaffolds developed and tested in pre-clinical and clinical scenarios in the past five years with a focus on their ability to overcome damage caused by MI. It will also describe how acellular scaffolds alone or in combination with biomolecules have been employed for MI treatment. A better understanding of acellular scaffolds potentialities may guide the development of customised and optimised therapeutic strategies for MI treatment.

Advances in bioactive glass-containing injectable hydrogel biomaterials for tissue regeneration

Successful tissue regeneration requires a scaffold with tailorable biodegradability, tissue-like mechanical properties, structural similarity to extracellular matrix (ECM), relevant bioactivity, and cytocompatibility. In recent years, injectable hydrogels have spurred increasing attention in translational medicine as a result of their tunable physicochemical properties in response to the surrounding environment. Furthermore, they have the potential to be implanted via minimally invasive procedures while enabling deep penetration, which is considered a feasible alternative to traditional open surgical procedures. However, polymeric hydrogels may lack sufficient stability and bioactivity in physiological environments. Composite hydrogels containing bioactive glass (BG) particulates, synergistically combining the advantages of their constituents, have emerged as multifunctional biomaterials with tailored mechanical properties and biological functionalities. This review paper highlights the recent advances in injectable composite hydrogel systems based on biodegradable polymers and BGs. The influence of BG particle geometry, composition, and concentration on gel formation, rheological and mechanical behavior as well as hydration and biodegradation of injectable hydrogels have been discussed. The applications of these composite hydrogels in tissue engineering are additionally described, with particular attention to bone and skin. Finally, the prospects and current challenges in the development of desirable injectable bioactive hydrogels for tissue regeneration are discussed to outline a roadmap for future research. STATEMENT OF SIGNIFICANCE: Developing a biomaterial that can be readily available for surgery, implantable via minimally invasive procedures, and be able to effectively stimulate tissue regeneration is one of the grand challenges in modern biomedicine. This review summarizes the state-of-the-art of injectable bioactive glass-polymer composite hydrogels to address several challenges in bone and soft tissue repair. The current limitations and the latest evolutions of these composite biomaterials are critically examined, and the roles of design parameters, such as composition, concentration, and size of the bioactive phase, and polymer-glass interactions on the rheological, mechanical, biological, and overall functional performance of hydrogels are detailed. Existing results and new horizons are discussed to provide a state-of-the-art review that may be useful for both experienced and early-stage researchers in the biomaterials community.

Modulating degradation of sodium alginate/bioglass hydrogel for improving tissue infiltration and promoting wound healing

More and more studies have recognized that the nanosized pores of hydrogels are too small for cells to normally grow and newly formed tissue to infiltrate, which impedes tissue regeneration. Recently, hydrogels with macropores and/or controlled degradation attract more and more attention for solving this problem. Sodium alginate/Bioglass (SA/BG) hydrogel, which has been reported to be an injectable and bioactive hydrogel, is also limited to be used as tissue engineering scaffolds due to its nanosized pores. Therefore, in this study, degradation of SA/BG hydrogel was modulated by grafting deferoxamine (DFO) to SA. The functionalized grafted DFO-SA (G-DFO-SA) was used to form G-DFO-SA/BG injectable hydrogel. In vitro degradation experiments proved that, compared to SA/BG hydrogel, G-DFO-SA/BG hydrogel had a faster mass loss and structural disintegration. When the hydrogels were implanted subcutaneously, G-DFO-SA/BG hydrogel possessed a faster degradation and better tissue infiltration as compared to SA/BG hydrogel. In addition, in a rat full-thickness skin defect model, wound healing studies showed that, G-DFO-SA/BG hydrogel significantly accelerated wound healing process by inducing more blood vessels formation. Therefore, G-DFO-SA/BG hydrogel can promote tissue infiltration and stimulate angiogenesis formation, which suggesting a promising application potential in tissue regeneration.

Bioactive Materials for Soft Tissue Repair

Over the past decades, age-related pathologies have increased abreast the aging population worldwide. The increased age of the population indicates that new tools, such as biomaterials/scaffolds for damaged tissues, which display high efficiency, effectively and in a limited period of time, for the regeneration of the body's tissue are needed. Indeed, scaffolds can be used as templates for three-dimensional tissue growth in order to promote the tissue healing stimulating the body's own regenerative mechanisms. In tissue engineering, several types of biomaterials are employed, such as bioceramics including calcium phosphates, bioactive glasses, and glass-ceramics. These scaffolds seem to have a high potential as biomaterials in regenerative medicine. In addition, in conjunction with other materials, such as polymers, ceramic scaffolds may be used to manufacture composite scaffolds characterized by high biocompatibility, mechanical efficiency and load-bearing capabilities that render these biomaterials suitable for regenerative medicine applications. Usually, bioceramics have been used to repair hard tissues, such as bone and dental defects. More recently, in the field of soft tissue engineering, this form of scaffold has also shown promising applications. Indeed, soft tissues are continuously exposed to damages, such as burns or mechanical traumas, tumors and degenerative pathology, and, thereby, thousands of people need remedial interventions such as biomaterials-based therapies. It is known that scaffolds can affect the ability to bind, proliferate and differentiate cells similar to those of autologous tissues. Therefore, it is important to investigate the interaction between bioceramics and somatic/stem cells derived from soft tissues in order to promote tissue healing. Biomimetic scaffolds are frequently employed as drug-delivery system using several therapeutic molecules to increase their biological performance, leading to ultimate products with innovative functionalities. This review provides an overview of essential requirements for soft tissue engineering biomaterials. Data on recent progresses of porous bioceramics and composites for tissue repair are also presented.