Regenerative medicine, encompassing various therapeutic approaches aimed at tissue repair and regeneration, has emerged as a promising field in the realm of physical therapy. Aim: This comprehensive review seeks to explore the evolving role of regenerative medicine within the domain of physical therapy, highlighting its potential applications, challenges, and current trends. Researchers selected publications of pertinent studies from 2015 to 2024 and performed an exhaustive review of electronic databases such as PubMed, Embase, and Google Scholar using the targeted keywords \"regenerative medicine\", \"rehabilitation\", \"tissue repair\", and \"physical therapy\" to screen applicable studies according to preset parameters for eligibility, then compiled key insights from the extracted data. Several regenerative medicine methods that are applied in physical therapy, in particular, stem cell therapy, platelet-rich plasma (PRP), tissue engineering, and growth factor treatments, were analyzed in this research study. The corresponding efficacy of these methods in the recovery process were also elaborated, including a discussion on facilitating tissue repair, alleviating pain, and improving functional restoration. Additionally, this review reports the challenges concerning regenerative therapies, among them the standardization of protocols, safety concerns, and ethical issues. Regenerative medicine bears considerable potential as an adjunctive therapy in physiotherapy, providing new pathways for improving tissue repair and functional results. Although significant strides have been made in interpreting the potential of regenerative techniques, further research is warranted to enhance protocols, establish safety profiles, and increase access and availability. Merging regenerative medicine into the structure of physical therapy indicates a transformative alteration in clinical practice, with the benefit of increasing patient care and improving long-term results.

Microcarrier applications have made great advances in tissue engineering in recent years, which can load cells, drugs, and bioactive factors. These microcarriers can be minimally injected into the defect to help reconstruct a good microenvironment for tissue repair. In order to achieve more ideal performance and face more complex tissue damage, an increasing amount of effort has been focused on microcarriers that can actively respond to external stimuli. These microcarriers have the functions of directional movement, targeted enrichment, material release control, and providing signals conducive to tissue repair. Given the high controllability and designability of magnetic and electroactive microcarriers, the research progress of these microcarriers is highlighted in this review. Their structure, function and applications, potential tissue repair mechanisms, and challenges are discussed. In summary, through the design with clinical translation ability, meaningful and comprehensive experimental characterization, and in-depth study and application of tissue repair mechanisms, stimuli-responsive microcarriers have great potential in tissue repair.

The repair and regeneration of the injured tissues or organs is a major challenge for biomedicine, and the emerging 3D bioprinting technology as a class of promising techniques in biomedical research for the development of tissue engineering and regenerative medicine. Chitosan-based bioinks, as the natural biomaterials, are considered as ideal materials for 3D bioprinting to design and fabricate the various scaffold due to their unique dynamic reversibility and fantastic biological properties. Our review aims to provide an overview of chitosan-based bioinks for in vitro tissue repair and regeneration, starting from modification of chitosan that affect these bioprinting processes. In addition, we summarize the advances in chitosan-based bioinks used in the various 3D printing strategies. Moreover, the biomedical applications of chitosan-based bioinks are discussed, primarily centered on regenerative medicine and tissue modeling engineering. Finally, current challenges and future opportunities in this field are discussed. The combination of chitosan-based bioinks and 3D bioprinting will hold promise for developing novel biomedical scaffolds for tissue or organ repair and regeneration.

In recent years, an increasing number of scientists have focused on conducting experiments on laser ablation of bone tissue. The purpose of this study was to summarize the prognosis of tissue and the extent of thermal damage in past hard tissue ablation experiments, and review the evidence for the feasibility of laser osteotomy in surgery. An electronic search of PubMed, China National Knowledge Infrastructure (CNKI), and Web of Science (WOS) for relevant English-language articles published through June 2023 was conducted. This review includes 48 literature reports on laser ablation of hard tissues from medical and biological perspectives. It summarizes previous studies in which the ideal ablation rate, depth of ablation, and minimal damage to bone tissue and surrounding soft tissues were achieved by changing the laser type, optimizing the laser parameter settings, or adding adjuvant devices. By observing their post-operative healing and inflammatory response, this review aims to provide a better understanding of pulsed laser ablation of hard tissues. Previous studies suggest that laser osteotomy has yielded encouraging results in bone resection procedures. We believe that low or even no thermal damage can be achieved by experimentally selecting a suitable laser type, optimizing laser parameters such as pulse duration and frequency, or adding additional auxiliary cooling devices. However, the lack of clinical studies makes it difficult to conclusively determine whether laser osteotomy is superior in clinical applications.

There are many studies on specific macromolecules and their contributions to tissue repair. Macromolecules have supporting and protective effects in organisms and can help regrow, reshape, and promote self-repair and regeneration of damaged tissues. Macromolecules, such as proteins, nucleic acids, and polysaccharides, can be constructed into hydrogels for the preparation of slow-release drug agents, carriers for cell culture, and platforms for gene delivery. Hydrogels and microspheres are fabricated by chemical crosslinking or mixed co-deposition often used as scaffolds, drug carriers, or cell culture matrix, provide proper mechanical support and nutrient delivery, a well-conditioned environment that to promote the regeneration and repair of damaged tissues. This review provides a comprehensive overview of recent developments in the construction of macromolecules into hydrogels and microspheres based on the proteins, nucleic acids, polysaccharides and other polymer and their application in tissue repair. We then discuss the latest research trends regarding the advantages and disadvantages of these composites in repair tissue. Further, we examine the applications of microspheres/hydrogels in different tissue repairs, such as skin tissue, cartilage, tumor tissue, synovial, nerve tissue, and cardiac repair. The review closes by highlighting the challenges and prospects of microspheres/hydrogels composites.

Angiogenesis is the formation of new blood vessel from existing vessels and is a critical first step in tissue repair following chronic disturbances in healing and degenerative tissues. Chronic pathoanatomic tissues are characterized by a high number of inflammatory cells; an overexpression of inflammatory mediators; such as tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1); the presence of mast cells, T cells, reactive oxygen species, and matrix metalloproteinases; and a decreased angiogenic capacity. Multiple studies have demonstrated that autologous orthobiological cellular preparations (e.g., platelet-rich plasma (PRP)) improve tissue repair and regenerate tissues. There are many PRP devices on the market. Unfortunately, they differ greatly in platelet numbers, cellular composition, and bioformulation. PRP is a platelet concentrate consisting of a high concentration of platelets, with or without certain leukocytes, platelet-derived growth factors (PGFs), cytokines, molecules, and signaling cells. Several PRP products have immunomodulatory capacities that can influence resident cells in a diseased microenvironment, inducing tissue repair or regeneration. Generally, PRP is a blood-derived product, regardless of its platelet number and bioformulation, and the literature indicates both positive and negative patient treatment outcomes. Strangely, the literature does not designate specific PRP preparation qualifications that can potentially contribute to tissue repair. Moreover, the literature scarcely addresses the impact of platelets and leukocytes in PRP on (neo)angiogenesis, other than a general one-size-fits-all statement that \"PRP has angiogenic capabilities\". Here, we review the cellular composition of all PRP constituents, including leukocytes, and describe the importance of platelet dosing and bioformulation strategies in orthobiological applications to initiate angiogenic pathways that re-establish microvasculature networks, facilitating the supply of oxygen and nutrients to impaired tissues.

Spinal cord injury (SCI) is a disease of the central nervous system often caused by accidents, and its prognosis is unsatisfactory, with long-term adverse effects on patients\' lives. The key to its treatment lies in the improvement of the microenvironment at the injury and the reconstruction of axons, and tissue repair is a promising therapeutic strategy. Hydrogel is a three-dimensional mesh structure with high water content, which has the advantages of biocompatibility, degradability, and adjustability, and can be used to fill pathological defects by injectable flowing hydrophilic material in situ to accurately adapt to the size and shape of the injury. Hydrogels mimic the natural extracellular matrix for cell colonization, guide axon extension, and act as a biological scaffold, which can be used as an excellent carrier to participate in the treatment of SCI. The addition of different materials to make composite hydrogel scaffolds can further enhance their performance in all aspects. In this paper, we introduce several typical composite hydrogels and review the research progress of hydrogel for SCI to provide a reference for the clinical application of hydrogel therapy for SCI.

Temperature-sensitive drug delivery systems (TSDDS) are one of the systems that have received more attention in medical science these days due to their advantages. As these systems are sensitive to temperature, drug delivery to the target becomes more specific. Temperature-sensitive nanogels have many applications, including microbial infections, cancer therapy, transdermal use, and tissue repair. These systems are characterized by minimal toxicity, improved therapeutic efficacy, and reduced exposure to normal cells. This mini-review is prepared with different types of temperature-sensitive nanogel formation, release mechanisms, and their different applications. Various systems reported under these categories for targeted and controlled delivery of different classes of drugs, such as anti-cancer and antibiotic drugs with special emphasis on anti-cancer drugs and tissue healing, are discussed in this mini-review.

Plasma preparations originating from the centrifugation of blood samples, such as platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), have proven useful for the treatment of gingival recession due to their rich concentration of cells and cytokines fundamental in the mechanisms of both soft tissue and hard tissue repair. Depending on the preparation method used to generate PRP and PRF, different concentrations of plasma elements and physicochemical characteristics can be obtained. This study sought to perform an integrative literature review to compile the available data on different protocols for generating plasma preparations and their indications, benefits, and results. A descriptive research method was adopted for assessing the literature on processes for obtaining PRF, and articles indexed in the MEDLINE database were searched. The literature review showed that changes in the PRF protocols for obtaining blood concentrates have led to better isolation of cells and growth factors and more promising results in tissue repair. The evolution in protocols has resulted in various forms of PRF with different components: (1) a membrane that aggregates platelets and leukocytes (L-PRF); (2) a PRF rich in growth factors and cytokines, known as advanced PRF (A-PRF); (3) a liquid phase called injectable PRF (I-PRF) that shows greater cell accumulation than L-PRF; (4) A-PRF plus (A-PDF+), which improved the release of growth factors for a period of 10 days; and (5) concentrated PRF (C-PRF) obtained by progressive pipetting, which has the greatest cell accumulation among all of the types of platelet aggregates. Subsequently, the observation that the speed of centrifugation influenced the acquisition of specific cells resulted in the development of the low-speed centrifugation concept. Then, it was determined that reduction of the relative centrifugation forces significantly increased the number of platelets, leukocytes, and growth factors. Recently, evaluation of the centrifugation angle revealed greater entrapment of large cells, such as red blood cells, when centrifugation was changed from a fixed to a horizontal angle. Tissue bioengineering studies are allowing for significant advances in the process of obtaining blood components and enabling their use for tissue repair with greater predictability and less morbidity.

Tissue repair after trauma and infection has always been a difficult problem in regenerative medicine. Hydrogels have become one of the most important scaffolds for tissue engineering due to their biocompatibility, biodegradability and water solubility. Especially, the stiffness of hydrogels is a key factor, which influence the morphology of mesenchymal stem cells (MSCs) and their differentiation. The researches on this point are meaningful to the field of tissue engineering. Herein, this review focus on the design of hydrogels with different stiffness and their effects on the behavior of MSCs. In addition, the effect of hydrogel stiffness on the phenotype of macrophages is introduced, and then the relationship between the phenotype changes of macrophages on inflammatory response and tissue repair is discussed. Finally, the future application of hydrogels with a certain stiffness in regenerative medicine and tissue engineering has been prospected.