Biomaterials-Mediated Engineering of the Immune System.

Modulation of the immune system is an important therapeutic strategy in a wide range of diseases, and is fundamental to the development of vaccines. However, optimally safe and effective immunotherapy requires precision in the delivery of stimulatory cues to the right cells at the right place and time, to avoid toxic overstimulation in healthy tissues or incorrect programming of the immune response. To this end, biomaterials are being developed to control the location, dose, and timing of vaccines and immunotherapies. Here we discuss fundamental concepts of how biomaterials are used to enhance immune modulation, and evidence from preclinical and clinical studies of how biomaterials-mediated immune engineering can impact the development of new therapeutics. We focus on immunological mechanisms of action and in vivo modulation of the immune system, and we also discuss challenges to be overcome to speed translation of these technologies to the clinic.

Emerging Modalities and Implantable Technologies for Neuromodulation.

Techniques for neuromodulation serve as effective routes to care of patients with many types of challenging conditions. Continued progress in this field of medicine will require (1) improvements in our understanding of the mechanisms of neural control over organ function and (2) advances in technologies for precisely modulating these functions in a programmable manner. This review presents recent research on devices that are relevant to both of these goals, with an emphasis on multimodal operation, miniaturized dimensions, biocompatible designs, advanced neural interface schemes, and battery-free, wireless capabilities. A future that involves recording and modulating neural activity with such systems, including those that exploit closed-loop strategies and/or bioresorbable designs, seems increasingly within reach.

Injectable tissue prosthesis for instantaneous closed-loop rehabilitation.

To construct tissue-like prosthetic materials, soft electroactive hydrogels are the best candidate owing to their physiological mechanical modulus, low electrical resistance and bidirectional stimulating and recording capability of electrophysiological signals from biological tissues1,2. Nevertheless, until now, bioelectronic devices for such prostheses have been patch type, which cannot be applied onto rough, narrow or deep tissue surfaces3-5. Here we present an injectable tissue prosthesis with instantaneous bidirectional electrical conduction in the neuromuscular system. The soft and injectable prosthesis is composed of a biocompatible hydrogel with unique phenylborate-mediated multiple crosslinking, such as irreversible yet freely rearrangeable biphenyl bonds and reversible coordinate bonds with conductive gold nanoparticles formed in situ by cross-coupling. Closed-loop robot-assisted rehabilitation by injecting this prosthetic material is successfully demonstrated in the early stage of severe muscle injury in rats, and accelerated tissue repair is achieved in the later stage.

Rational Design of Biomaterials to Potentiate Cancer Thermal Therapy.

Cancer thermal therapy, also known as hyperthermia therapy, has long been exploited to eradicate mass lesions that are now defined as cancer. With the development of corresponding technologies and equipment, local hyperthermia therapies such as radiofrequency ablation, microwave ablation, and high-intensity focused ultrasound, have has been validated to effectively ablate tumors in modern clinical practice. However, they still face many shortcomings, including nonspecific damages to adjacent normal tissues and incomplete ablation particularly for large tumors, restricting their wide clinical usage. Attributed to their versatile physiochemical properties, biomaterials have been specially designed to potentiate local hyperthermia treatments according to their unique working principles. Meanwhile, biomaterial-based delivery systems are able to bridge hyperthermia therapies with other types of treatment strategies such as chemotherapy, radiotherapy and immunotherapy. Therefore, in this review, we discuss recent progress in the development of functional biomaterials to reinforce local hyperthermia by functioning as thermal sensitizers to endow more efficient tumor-localized thermal ablation and/or as delivery vehicles to synergize with other therapeutic modalities for combined cancer treatments. Thereafter, we provide a critical perspective on the further development of biomaterial-assisted local hyperthermia toward clinical applications.

Therapeutic synthetic and natural materials for immunoengineering.

Immunoengineering is a rapidly evolving field that has been driving innovations in manipulating immune system for new treatment tools and methods. The need for materials for immunoengineering applications has gained significant attention in recent years due to the growing demand for effective therapies that can target and regulate the immune system. Biologics and biomaterials are emerging as promising tools for controlling immune responses, and a wide variety of materials, including proteins, polymers, nanoparticles, and hydrogels, are being developed for this purpose. In this review article, we explore the different types of materials used in immunoengineering applications, their properties and design principles, and highlight the latest therapeutic materials advancements. Recent works in adjuvants, vaccines, immune tolerance, immunotherapy, and tissue models for immunoengineering studies are discussed.

Functionalised biomaterials as synthetic extracellular matrices to promote vascularisation and healing of diabetic wounds.

Diabetic foot ulcers (DFU) are a type of chronic wound that constitute one of the most serious and debilitating complications associated with diabetes. The lack of clinically efficacious treatments to treat these recalcitrant wounds can lead to amputations for those worst affected. Biomaterial-based approaches offer great hope in this regard, as they provide a template for cell infiltration and tissue repair. However, there is an additional need to treat the underlying pathophysiology of DFUs, in particular insufficient vascularization of the wound which significantly hampers healing. Thus, the addition of pro-angiogenic moieties to biomaterials is a promising strategy to promote the healing of DFUs and other chronic wounds. In this review, we discuss the potential of biomaterials as treatments for DFU and the approaches that can be taken to functionalise these biomaterials such that they promote vascularisation and wound healing in pre-clinical models.

Biomaterial and cellular implants: foreign surfaces where immunity and coagulation meet.

Exposure of blood to a foreign surface in the form of a diagnostic or therapeutic biomaterial device or implanted cells or tissue elicits an immediate, evolutionarily conserved thromboinflammatory response from the host. Primarily designed to protect against invading organisms after an injury, this innate response features instantaneous activation of several blood-borne, highly interactive, well-orchestrated cascades and cellular events that limit bleeding, destroy and eliminate the foreign substance or cells, and promote healing and a return to homeostasis via delicately balanced regenerative processes. In the setting of blood-contacting synthetic or natural biomaterials and implantation of foreign cells or tissues, innate responses are robust, albeit highly context specific. Unfortunately, they tend to be less than adequately regulated by the host's natural anticoagulant or anti-inflammatory pathways, thereby jeopardizing the functional integrity of the device, as well as the health of the host. Strategies to achieve biocompatibility with a sustained return to homeostasis, particularly while the device remains in situ and functional, continue to elude scientists and clinicians. In this review, some of the complex mechanisms by which biomaterials and cellular transplants provide a "hub" for activation and amplification of coagulation and immunity, thromboinflammation, are discussed, with a view toward the development of innovative means of overcoming the innate challenges.

Ex Vivo Surface Decoration of Phenylboronic Acid onto Natural Killer Cells for Sialic Acid-Mediated Versatile Cancer Cell Targeting.

Phenylboronic acid (PBA) has been highly acknowledged as a significant cancer recognition moiety in sialic acid-overexpressing cancer cells. In this investigation, lipid-mediated biomaterial integrated PBA molecules onto the surface of natural killer (NK) cells to make a receptor-mediated immune cell therapeutic module. Therefore, a 1,2-distearoyl-sn-glycero-3-phosphorylethanolamine (DSPE) lipid-conjugated di-PEG-PBA (DSPEPEG-di(PEG-PBA) biomaterial was synthesized. The DSPEPEG-di(PEG-PBA) biomaterial exhibited a high affinity for sialic acid (SA), confirmed by fluorescence spectroscopy at pH 6.5 and 7.4. DSPEPEG-di(PEG-PBA) was successfully anchored onto NK cell surfaces (PBA-NK), and this biomaterial maintains intrinsic properties such as viability, ligand availability (FasL & TRAIL), and cytokine secretion response to LPS. The anticancer efficacy of PBA-NK cells was evaluated against 2D cancer cells (MDA-MB-231, HepG2, and HCT-116) and 3D tumor spheroids of MDA-MB-231 cells. PBA-NK cells exhibited greatly enhanced anticancer effects against SA-overexpressing cancer cells. Thus, PBA-NK cells represent a new anticancer strategy for cancer immunotherapy.

Bacterial cellulose as an ideal potential treatment for burn wounds: A comprehensive review.

Burn wound regeneration is a complex process, which has many serious challenges such as slow wound healing, secondary infection, and inflammation. Therefore, it is essential to utilise appropriate biomaterials to accelerate and guide the wound healing process. Bacterial cellulose (BC), a natural polymer synthesised by some bacteria, has attracted much attention for wound healing applications due to its unique properties including excellent physicochemical and mechanical properties, simple purification process, three-dimensional (3D) network structure similar to extracellular matrix, high purity, high water holding capacity and significant permeability to gas and liquid. BC's lack of antibacterial activity significantly limits its biomedical and tissue engineering application, but adding antimicrobial agents to it remarkably improves its performance in tissue regeneration applications. Burn wound healing is a complex long-lasting process. Using biomaterials in wound treatment has shown that they can satisfactorily accelerate wound healing. The purpose of this review is to elaborate on the importance of BC-based structures as one of the most widely used modern wound dressings in the treatment of burn wounds. In addition, the combination of various drugs, agents, cells and biomolecules with BC to expand its application in burn injury regeneration is discussed. Finally, the main challenges and future development direction of BC-based structures for burn wound repair are considered. The four most popular search engines PubMed/MEDLINE, Science Direct, Scopus and Google Scholar were used to help us find relevant papers. The most frequently used keywords were bacterial cellulose, BC-based biocomposite, wound healing, burn wound and vascular graft.

Engineered Hemostatic Biomaterials for Sealing Wounds.

Hemostatic biomaterials show great promise in wound control for the treatment of uncontrolled bleeding associated with damaged tissues, traumatic wounds, and surgical incisions. A surge of interest has been directed at boosting hemostatic properties of bioactive materials via mechanisms triggering the coagulation cascade. A wide variety of biocompatible and biodegradable materials has been applied to the design of hemostatic platforms for rapid blood coagulation. Recent trends in the design of hemostatic agents emphasize chemical conjugation of charged moieties to biomacromolecules, physical incorporation of blood-coagulating agents in biomaterials systems, and superabsorbing materials in either dry (foams) or wet (hydrogel) states. In addition, tough bioadhesives are emerging for efficient and physical sealing of incisions. In this Review, we highlight the biomacromolecular design approaches adopted to develop hemostatic bioactive materials. We discuss the mechanistic pathways of hemostasis along with the current standard experimental procedures for characterization of the hemostasis efficacy. Finally, we discuss the potential for clinical translation of hemostatic technologies, future trends, and research opportunities for the development of next-generation surgical materials with hemostatic properties for wound management.

Comprehensive review of composition, properties, clinical applications, and future perspectives of calcium-enriched mixture (CEM) cement: a systematic analysis.

This review aims to comprehensively explore calcium-enriched mixture (CEM) cement as a crucial biomaterial in dentistry/endodontics. With its growing clinical relevance, there is a need to evaluate its composition, chemical/physical/biological properties, clinical applications, and future perspectives to provide clinicians/researchers with a detailed understanding of its potential in endodontic procedures. Through systematic analysis of available evidence, we assess the advantages/limitations of CEM cement, offering valuable insights for informed decision-making in dental/endodontic practice. Our findings highlight the commendable chemical/physical properties of CEM cement, including handling characteristics, alkalinity, color stability, bioactivity, biocompatibility, sealing ability, and antimicrobial properties. Importantly, CEM cement has shown the potential in promoting regenerative processes, such as dentinogenesis and cementogenesis. It has demonstrated successful outcomes in various clinical applications, including vital pulp therapy techniques, endodontic surgery, open apices management, root resorption/perforation repair, and as an orifice/root canal obturation material. The efficacy and reliability of CEM cement in diverse clinical scenarios underscore its effectiveness in endodontic practice. However, we emphasize the need for well-designed clinical trials with long-term follow-up to further substantiate the full potential of CEM cement. This review serves as a robust reference for researchers/practitioners, offering an in-depth exploration of CEM cement and its multifaceted roles in contemporary dentistry/endodontics.

Improvement effects of transplanting pancreatic islet that previously incubated with biomaterials on the diabetic nephropathy in STZ- diabetic rats.

BACKGROUND: Islet transplantation is an effective treatment for diabetes or even its complications. Aim of this study is to investigate efficacy of biomaterial treated islet transplantation on treating diabetic nephropathy. METHODS: Male rats were randomly divided into 6 groups; Control, diabetic control, diabetic transplanted with untreated islets, with platelet rich plasma treated islets, with pancreatic islets homogenate treated islets, or with these biomaterials combination treated islets. Islets cultured with biomaterials and transplanted to diabetic rats. After 60 days, biochemical, oxidative stress, and stereological parameters were assessed. RESULTS: Serum albumin and BUN concentration, decreased and increased respectively, Oxidative stress of kidney impaired, kidney weight, volume of kidney, cortex, medulla, glomerulus, proximal and distal tubules, collecting ducts, vessels, inflammatory, necrotic and fibrotic tissue in diabetic group increased compared to control group (p < 0.001). In treated groups, especially pancreatic islets homogenate treated islets transplanting animals, there was significant changes in kidney weight, and volume of kidney, proximal and distal tubules, Henle's loop and collecting ducts compared with diabetic group (p = 0.013 to p < 0.001). Combination treated islets animals showed significant increase in vessel volume compared to diabetic group (p < 0.001). Necrotic and fibrotic tissue significantly decreased in islets treated than untreated islet animals, it was higher in pancreatic islets homogenate, and combination treated islets groups (p = 0.001). CONCLUSIONS: Biomaterials treated islets transplanting could improve diabetic nephropathy. Improvement of oxidative stress followed by controlling glucose level, and effects of growth factors presenting in biomaterials can be considered as capable underlying mechanism of ameliorating inflammatory, necrotic and fibrotic tissue volume.

Editorial Commentary: Anterior Cruciate Ligament Repair or Reconstruction With Internal Bracing, for Properly Indicated Patients, Is Safe, Biocompatible, and Biomimetic.

Anterior cruciate ligament (ACL) reconstruction with internal bracing (IB)-and ACL repair with IB when indicated-reduces graft or repair failure. IB is safe and protects ligament reconstructions and repairs. The IB construct should not be misunderstood as a synthetic ligament. To be effective, suture tape must be independently secured with the knee in full extension, reflecting the terminal length of the ACL. Regardless of graft type, the graft must be cyclically tensioned independent of the IB to allow for creep, and when properly performed, this significantly increases the ultimate tensile strength of the construct and reduces graft elongation, without stress shielding. Thus, the generic term "suture augmentation" may be misleading because the successful results reported apply to the IB technique. In our experience, the failure rate after ACL reconstruction with IB is 1% at the 5-year follow-up period. Notably, these results were achieved without an additional lateral extra-articular procedure.

Applications of Extracellular Matrix Biomaterial in Tongue Reconstruction.

Tongue neoplasms are common in the head and neck region and are primarily treated through surgical interventions. Various reconstruction techniques, such as primary closure, skin grafts, skin substitute biomaterials, and free tissue transfer, are used to address the resulting defects. This study provides an overview of our experience utilizing extracellular matrix-based biomaterials (ECM) for the reconstruction of tongue defects and evaluates the mean volumetric size of postsurgical tongue. This retrospective case series evaluated subjects with tongue defects secondary to benign or malignant resections who underwent reconstruction with ECM-based biomaterials at Ascension Hospital from July 2022 to May 2023. Descriptive variables were collected, and descriptive statistical analyses were conducted. The primary outcome was the volume of postsurgical defect reconstructed. Twenty-five subjects were included: 10 had benign pathology and 15 had malignancy. The mean reconstructed defect volume was 12.65 cm 3 , ranging between 2 and 35 cm 3 . Postoperative bleeding, mainly linked to anticoagulation medication, occurred in 20% (n=5) of the cases, and the rate of need for additional procedures was 8%. In conclusion, ECM-based biomaterials are suitable for reconstructing varying sizes of postsurgical tongue defects with no donor-site morbidity. Carefully considering patient factors, including anticoagulation medication use and defect volume, is essential in optimizing outcomes.

Closure of oroantral communications using heterologous biomaterials stabilized by porcine cortical lamina: A case series.

PURPOSE: To describe a surgical technique for oroantral communication closure and bone regeneration that can meet the needs of an effective, less invasive, and simpler surgery using approaches and biomaterials used in guided bone regeneration (GBR) techniques. The main objective was to close the communication, and the secondary was to achieve bone regeneration. METHODS: This retrospective and monocentric case series was conducted using data obtained from the medical records of 28 patients with oroantral communications with bone deficits greater than 3 mm and treated with heterologous cortico-cancellous graft covered with resorbable collagen membranes and heterologous cortical lamina. The primary outcome was closure of the communication, and the secondary outcome was bone augmentation, both tested radiographically and clinically. RESULTS: 28 subjects were treated consecutively for the closure of oroantral communications. The subjects included 16 men and 12 women. The mean age was 57.5 years. Closure was successful in all 28 cases, and radiographic control after 6 months showed bone regeneration in all the cases. This technique was effective in isolating the maxillary sinus from the oral cavity, showing results in terms of seal and healing, and bone regeneration. CLINICAL SIGNIFICANCE: Oroantral communications are frequent in dentistry, requiring special expertise and interventions affecting patient morbidity. The use of a heterologous cortical lamina can allow effective closure of the communication, preventing migration of pathological epithelia while increasing the bone ridge.

An Overview on the Big Players in Bone Tissue Engineering: Biomaterials, Scaffolds and Cells.

Presently, millions worldwide suffer from degenerative and inflammatory bone and joint issues, comprising roughly half of chronic ailments in those over 50, leading to prolonged discomfort and physical limitations. These conditions become more prevalent with age and lifestyle factors, escalating due to the growing elderly populace. Addressing these challenges often entails surgical interventions utilizing implants or bone grafts, though these treatments may entail complications such as pain and tissue death at donor sites for grafts, along with immune rejection. To surmount these challenges, tissue engineering has emerged as a promising avenue for bone injury repair and reconstruction. It involves the use of different biomaterials and the development of three-dimensional porous matrices and scaffolds, alongside osteoprogenitor cells and growth factors to stimulate natural tissue regeneration. This review compiles methodologies that can be used to develop biomaterials that are important in bone tissue replacement and regeneration. Biomaterials for orthopedic implants, several scaffold types and production methods, as well as techniques to assess biomaterials' suitability for human use-both in laboratory settings and within living organisms-are discussed. Even though researchers have had some success, there is still room for improvements in their processing techniques, especially the ones that make scaffolds mechanically stronger without weakening their biological characteristics. Bone tissue engineering is therefore a promising area due to the rise in bone-related injuries.

Hydrogel-Based Skin Regeneration.

The skin is subject to damage from the surrounding environment. The repair of skin wounds can be very challenging due to several factors such as severe injuries, concomitant infections, or comorbidities such as diabetes. Different drugs and wound dressings have been used to treat skin wounds. Tissue engineering, a novel therapeutic approach, revolutionized the treatment and regeneration of challenging tissue damage. This field includes the use of synthetic and natural biomaterials that support the growth of tissues or organs outside the body. Accordingly, the demand for polymer-based therapeutic strategies for skin tissue defects is significantly increasing. Among the various 3D scaffolds used in tissue engineering, hydrogel scaffolds have gained special significance due to their unique properties such as natural mimicry of the extracellular matrix (ECM), moisture retention, porosity, biocompatibility, biodegradability, and biocompatibility properties. First, this article delineates the process of wound healing and conventional methods of treating wounds. It then presents an examination of the structure and manufacturing methods of hydrogels, followed by an analysis of their crucial characteristics in healing skin wounds and the most recent advancements in using hydrogel dressings for this purpose. Finally, it discusses the potential future advancements in hydrogel materials within the realm of wound healing.

Natural Compounds and Biomimetic Engineering to Influence Fibroblast Behavior in Wound Healing.

Throughout history, natural products have played a significant role in wound healing. Fibroblasts, acting as primary cellular mediators in skin wound healing, exhibit behavioral responses to natural compounds that can enhance the wound healing process. Identifying bioactive natural compounds and understanding their impact on fibroblast behavior offers crucial translational opportunities in the realm of wound healing. Modern scientific techniques have enabled a detailed understanding of how naturally derived compounds modulate wound healing by influencing fibroblast behavior. Specific compounds known for their wound healing properties have been identified. Engineered biomimetic compounds replicating the natural wound microenvironment are designed to facilitate normal healing. Advanced delivery methods operating at micro- and nano-scales have been developed to effectively deliver these novel compounds through the stratum corneum. This review provides a comprehensive summary of the efficacy of natural compounds in influencing fibroblast behavior for promoting wound regeneration and repair. Additionally, it explores biomimetic engineering, where researchers draw inspiration from nature to create materials and devices mimicking physiological cues crucial for effective wound healing. The review concludes by describing novel delivery mechanisms aimed at enhancing the bioavailability of natural compounds. Innovative future strategies involve exploring fibroblast-influencing pathways, responsive biomaterials, smart dressings with real-time monitoring, and applications of stem cells. However, translating these findings to clinical settings faces challenges such as the limited validation of biomaterials in large animal models and logistical obstacles in industrial production. The integration of ancient remedies with modern approaches holds promise for achieving effective and scar-free wound healing.

Biomaterials in Drug Delivery: Advancements in Cancer and Diverse Therapies-Review.

Nano-sized biomaterials are innovative drug carriers with nanometric dimensions. Designed with biocompatibility in mind, they enable precise drug delivery while minimizing side effects. Controlled release of therapeutic substances enhances efficacy, opening new possibilities for treating neurological and oncological diseases. Integrated diagnostic-therapeutic nanosystems allow real-time monitoring of treatment effectiveness, which is crucial for therapy personalization. Utilizing biomaterials as nano-sized carriers in conjunction with drugs represents a promising direction that could revolutionize the field of pharmaceutical therapy. Such carriers represent groundbreaking drug delivery systems on a nanometric scale, designed with biocompatibility in mind, enabling precise drug delivery while minimizing side effects. Using biomaterials in synergy with drugs demonstrates significant potential for a revolutionary impact on pharmaceutical therapy. Conclusions drawn from the review indicate that nano-sized biomaterials constitute an innovative tool that can significantly improve therapy effectiveness and safety, especially in treating neurological and oncological diseases. These findings should guide researchers towards further studies to refine nano-sized biomaterials, assess their effectiveness under various pathological conditions, and explore diagnostic-therapeutic applications. Ultimately, these results underscore the promising nature of nano-sized biomaterials as advanced drug carriers, ushering in a new era in nanomedical therapy.

Sustainable Silk-Based Particulate Systems for the Controlled Release of Pharmaceuticals and Bioactive Agents in Wound Healing and Skin Regeneration.

The increasing demand for innovative approaches in wound healing and skin regeneration has prompted extensive research into advanced biomaterials. This review focuses on showcasing the unique properties of sustainable silk-based particulate systems in promoting the controlled release of pharmaceuticals and bioactive agents in the context of wound healing and skin regeneration. Silk fibroin and sericin are derived from well-established silkworm production and constitute a unique biocompatible and biodegradable protein platform for the development of drug delivery systems. The controlled release of therapeutic compounds from silk-based particulate systems not only ensures optimal bioavailability but also addresses the challenges associated with conventional delivery methods. The multifaceted benefits of silk proteins, including their inherent biocompatibility, versatility, and sustainability, are explored in this review. Furthermore, the intricate mechanisms by which controlled drug release takes place from silk-based carriers are discussed.