Acellular Tissue Research Articles

Immediate Implant Placement with Soft Tissue Augmentation Using Acellular Dermal Matrix Versus Connective Tissue Graft: A Systematic Review and Meta-Analysis

This systematic review investigates the efficacy of using connective tissue grafting (CTG) versus an acellular dermal matrix (ADM) for soft tissue management in immediate implant placement (IIP). The study focuses on comparing the soft tissue thickness (STT) and keratinized tissue width (KTW) changes post-implantation. Adhering to the PRISMA guidelines, a comprehensive literature search was conducted, targeting randomized clinical trials and cohort studies involving soft tissue grafting in conjunction with IIP. Data extraction and analysis focused on STT and KTW measurements from baseline to follow-up intervals of at least 6 months. The statistical analyses included the weighted mean differences and heterogeneity assessments among the studies. The meta-analysis revealed no significant difference in the STT gain between CTG and ADM at 12 months, with the weighted mean differences favoring the control group but lacking statistical significance (CTG: 0.46 ± 0.53 mm, p = 0.338; ADM: 0.33 ± 0.44 mm, p = 0.459). The heterogeneity was high among the studies, with discrepancies notably influenced by individual study variations. Similarly, the changes in KTW were not significantly different between the two grafting materials. Conclusions: Both CTG and ADM are viable options for soft tissue management in IIP, with no significant difference in efficacy regarding the soft tissue thickness and keratinized tissue width outcomes. Future research should aim to minimize the heterogeneity and explore the long-term effects to better inform clinical decisions.

Freezing and bioreactor in the low-concentration detergents: A novel approach in the decellularization of small-diameter arteries.

Using decellularized small-diameter vascular bypass substitutes (<6 mm) is an efficient method for bypass grafting. A solution containing 0.5% SDS (weight/volume) is commonly used for extended periods to generate acellular tissues. However, this solution causes damage to the microfibril structure and alters the mechanical forces. Hence, the objective of this study is to reduce the concentration of SDS to preserve the structure and achieve efficient decellularization. The study employs a diluted solution of 0.3% SDS (weight/volume) to treat fresh and frozen swine small-diameter arteries, utilizing physical methods such as freezing and thawing. The effectiveness of cell removal was evaluated using histological analysis and the remaining DNA content of the sample. Furthermore, the acellular circuit also assesses the cytotoxicity and proliferation of HUVECs to gauge their safety. Through the use of 0.3% SDS, a bioreactor system, and freezing-thawing, the pig arteries are successfully decellularized, resulting in residual DNA levels of less than 50 ng/mg dry weight. This process does not cause any major changes to the biomechanical or structural properties of the arteries. The acellular samples exhibit no toxicity on the L929 cell line and promote the growth of HUVECs at their highest rate on the fourth day. This allows for the placement of acellular vascular grafts to evaluate physiological processes within the animal body. This is an important requirement in clinical blood vessel transplantation.

Prospective Randomized Trial of Humacyte's Acellular Tissue Engineered Vessel vs. Autologous Arteriovenous Fistula for Hemodialysis Access

Prospective Randomized Trial of Humacyte's Acellular Tissue Engineered Vessel vs. Autologous Arteriovenous Fistula for Hemodialysis Access

Pericardium decellularization in a one-day, two-step protocol.

Scaffolds used in tissue engineering can be obtained from synthetic or natural materials, always focusing the effort on mimicking the extracellular matrix of human native tissue. In this study, a decellularization process is used to obtain an acellular, biocompatible non-cytotoxic human pericardium graft as a bio-substitute. An enzymatic and hypertonic method was used to decellularize the pericardium. Histological analyses were performed to determine the absence of cells and ensure the integrity of the extracellular matrix (ECM). In order to measure the effect of the decellularization process on the tissue's biological and mechanical properties, residual genetic content and ECM biomolecules (collagen, elastin, and glycosaminoglycan) were quantified and the tissue's tensile strength was tested. Preservation of the biomolecules, a residual genetic content below 50ng/mg dry tissue, and maintenance of the histological structure provided evidence for the efficacy of the decellularization process, while preserving the ECM. Moreover, the acellular tissue retains its mechanical properties, as shown by the biomechanical tests. Our group has shown that the acellular pericardial matrix obtained through the super-fast decellularization protocol developed recently retains the desired biomechanical and structural properties, suggesting that it is suitable for a broad range of clinical indications.

Breaking through the eggshell: embryonic development of the premaxillary dentition in Lacerta agilis (Squamata: Unidentata) with special emphasis on the egg tooth

Abstract The egg tooth of squamates is a true tooth that allows them to break, tear, or cut the eggshell during hatching. In this clade there are some uncertainties concerning the egg tooth implantation geometry, the number of germs, and their fates during embryonic development. Here, we used X-ray microtomography and light microscopy, focusing on the egg tooth and remaining premaxillary teeth of the sand lizard (Lacerta agilis, Squamata: Unidentata). The developing egg tooth of this species passes through all the classic stages of tooth development. We did not find any evidence that the large size of the egg tooth is related to the merging of two egg tooth germs, which has recently been suggested to occur in snakes. Instead, this feature can be attributed to the delayed formation of the neighbouring regular premaxillary teeth. This might provide more resources to the developing egg tooth. At the last developmental stage, the egg tooth is a large, midline structure, bent forward as in most oviparous Unidentata. It is characterized by pleurodont implantation, and its base is attached to the pleura and a peculiar ridge of the alveolar bone. The attachment tissue contains periodontal ligament-like tissue, acellular cementum-like tissue, and alveolar bone.

Exosomes from Hypoxia Preconditioned Muscle-Derived Stem Cells Enhance Cell-Free Corpus Cavernosa Angiogenesis and Reproductive Function Recovery.

Tissue engineering for penile corpora cavernosa defects requires microvascular system reconstruction.GelMA hydrogels show promise for tissue regeneration. However, using stem cells faces challenges such as immune rejection, limited proliferation and differentiation, and biosafety concerns. Therefore, acellular tissue regeneration may avoid these issues. Exosomes are used from muscle-derived stem cells (MDSCs) to modify 3D-printed hydrogel scaffolds for acellular tissue regeneration. Hypoxia-preconditioned MDSC-derived exosomes are obtained to enhance the therapeutic effect. In contrast to normoxic exosomes (N-Exos), hypoxic exosomes (H-Exos) are found to markedly enhance the proliferation, migration, and capillary-like tube formation of human umbilical vein endothelial cells (HUVECs). High-throughput sequencing analysis of miRNAs isolated from both N-Exos and H-Exos revealed a significant upregulation of miR-21-5p in H-Exos following hypoxic preconditioning. Further validation demonstrated that the miR-21-5p/PDCD4 pathway promoted the proliferation of HUVECs. Epigallocatechin gallate (EGCG) is introduced to improve the mechanical properties and biocompatibility of GelMA hydrogels. EGCG-GelMA scaffolds loaded with different types of Exos are transplanted to repair rabbit penile corpora cavernosa defects, observed the blood flow and repair status of the defect site through color Doppler ultrasound and magnetic resonance imaging, and ultimately restored the rabbit penile erection function and successfully bred offspring. Thus, acellular hydrogel scaffolds offer an effective treatment for penile corpora cavernosa defects.

In vitro and in vivo investigation of chitosan/silk fibroin injectable interpenetrating network hydrogel with microspheres for cartilage regeneration

Articular cartilage is an avascular and almost acellular tissue with limited self-regenerating capabilities. Although injectable hydrogels have garnered a lot of attention as a promising treatment, a biocompatible hydrogel with adequate mechanical properties is yet to be created. In this study, an interpenetrating network hydrogel comprised of chitosan and silk fibroin was created through electrostatic and hydrophobic bonds, respectively. The polymeric network of the scaffold combined an effective microenvironment for cell activity with enhanced mechanical properties to address the current issues in cartilage scaffolds. Furthermore, microspheres (MS) were utilized for a controlled release of methylprednisolone acetate (MPA), around ~75 % after 35 days. The proposed scaffolds demonstrated great mechanical stability with ~0.047 MPa compressive moduli and ~145 kPa compressive strength. Moreover, the degradation rate of the samples (~45 % after 35 days) was optimized to match neo-cartilage formation. Furthermore, the use of natural biomaterials yielded good biocompatibility with ~76 % chondrocyte viability after 7 days. According to gross observation after 12 weeks the defect site of the treated groups was filled with minimally discernible boundary. These results were confirmed by histopathology assays were the treated groups showed higher chondrocyte count and collagen type II expression.

Acellular dermal matrix-assisted tissue expansion for giant congenital melanocytic nevi of the extremities and trunk in pediatric patients.

Tissue expansion for treating giant congenital melanocytic nevi (GCMN) is a commonly employed surgical method. However, the procedure's efficacy is often hindered by anatomical and histological characteristics as well as blood supply, particularly in the extremities and trunk. Enhancing expansion efficiency while reducing complications is thus a topic to be investigated, especially for pediatric patients undergoing rapid physical and psychological development with higher risks of non-compliance to medical instructions. To explore the effectiveness of expansion in extremities and trunk by immobilizing the acellular dermal matrix (ADM) in the gravitational force zone of inflating expanders. All patients involved in this research underwent ADM-assisted tissue expansion in either the extremities or trunk. ADM was fully flattened, securely fixed to the lower pole of the expander, and subsequently attached to the inner surface of the expanding flap. From 2021 to 2023, a total of nine pediatric patients with GCMN underwent the ADM-assisted tissue expansion. All patients achieved the desired expanding volume without experiencing petechiae, ecchymosis, or skin ulceration in the ADM-covered area. The process was well tolerated by all patients, with no reports of itching, pain, allergic reaction, or fever. During the flap transfer, the ADM was observed to be firmly adhered to the expanding flap with discernible capillary network. ADM-assisted tissue expansion demonstrates promise in augmenting expansion efficiency and reducing the time needed for surgical intervention in the extremities and trunk, thereby presenting significant clinical value for pediatric patients afflicted with GCMN.

A hospital-based study of prostate biopsy results in Indian males.

The prostate is a gland belonging to the male reproductive system. Aging results in the dysfunction of the prostate that may present as inflammation, enlargement, and cancer. Additionally, the diseases of the prostate including cancers are slow in progression, and therefore, it is difficult to diagnose them early. Hence, it is increasingly important for physicians to recommend histopathological examination of the prostate gland to identify, manage, and treat prostate cancers. This study was conducted to assess prostate diseases among biopsy specimen collected from patients with signs of prostate diseases. This prospective study was conducted in the Department of Pathology, Deccan College of Medical Sciences, Owaisi Hospital, Hyderabad, between June 2012 and September 2014. All gross specimens (n = 300) of the prostate such as the needle biopsies of the prostate, transurethral resection of the prostate (TURP) chips, and excised specimens of the prostate were included in the study. Histopathological examinations of the biopsies were performed for nuclear size, chromatin material, nucleoli, membrane thickness, irregularity, cytoplasmic granularity, staining, and cell border conspicuity. The biopsies were also assessed for lobule formation, secretions, polymorphonuclear leukocytes, lymphocytes, macrophages, connective tissue stromal cells, their arrangements, and acellular connective tissue material. Of 300 total prostatic biopsies performed, 56 (18.66%) were identified as inflammatory lesions of the prostate (prostatitis), 98 (32.66%) revealed benign prostatic lesions (benign prostatic hyperplasia (BPH)), 112 (37.33%) were identified as BPH with premalignant lesions, and 34 (11.33%) were revealed as malignant tumors of the prostate. Chronic prostatitis (67.85%) was the common inflammatory lesion. The majority (91.42%) revealed epithelial lesions compared to stromal lesions (08.58%). BPH was predominantly (28.00%) noticed among patients in the age group of 61-70 years. Prostatic intraepithelial neoplasia (PIN) was observed majorly (53.35%) in the age group of 61-70 years. Most of the prostatic cancers were identified as adenocarcinomas. However, three variants were also categorized as small cell carcinoma, signet ring cell carcinoma, and transitional cell carcinomas. The results reveal that prostatic adenocarcinomas are predominant among the study population. Additionally, prostatic diseases including cancer are commonly noticed among people belonging to the age group of 61-70 years. More than one-third of patients showed BPH with premalignant lesions, and a majority of the study population showed evidence of chronic prostatitis.

Abdominal Wall Reinforcement Using Acellular Tissue Matrix after Deep Inferior Epigastric Perforator Flap Harvest for Breast Reconstruction

Abdominal Wall Reinforcement Using Acellular Tissue Matrix after Deep Inferior Epigastric Perforator Flap Harvest for Breast Reconstruction

Viscoelastic Properties of Acellular Matrices of Porcine Esophageal Mucosa and Comparison with Acellular Matrices of Porcine Small Intestine Submucosa and Bovine Pericardium.

The aim of this study was to compare the viscoelastic properties of a decellularized mesh from the porcine esophagus, prepared by our group, with two commercial acellular tissues derived from porcine small intestine submucosa and bovine pericardium for use in medical devices. The tissues' viscoelastic properties were characterized by creep tests in tension, applying the load in the direction of the fibers or the transverse direction, and also by dynamic-shear mechanical tests between parallel plates or in tension at frequencies between 0.1 and 35 Hz. All the tests were performed in triplicate at a constant temperature of 37 °C immersed in distilled water. The tissues' surface and cross-sectional microstructure were observed by scanning electron microscopy (SEM) to characterize the orientation of the fibers. The matrices of the porcine esophagus present an elastic modulus in the order of 60 MPa when loaded in the longitudinal direction while those of the porcine intestine submucosa and bovine pericardium have an elastic modulus below 5 MPa. Nevertheless, the shear modulus of bovine pericardium nearly triplicates that of the esophageal matrix. The viscoelasticity of decellularized esophageal mucosa is characterized by a fast change in the creep compliance with time. The slope of the creep curve in the double logarithmic plot is twice that of the control samples. These results are consistent with the microstructure observed under electron microscopy regarding the orientation of the fibers that make up the matrices.

The Use of Acellular Tissue Matrices in Gender-Affirming Surgery: Review of the Literature and Institutional Experience.

Wound healing complications are not uncommon after genital gender-affirming surgery and can pose significant challenges for the reconstructive surgeon. Acellulartissue matrices are products that contain extracellular matrix compounds without living cells and are used to expedite and improve wound healing.Some of these products have been described for a variety of different indicationsin gender-affirming surgery. In this paper, the authors present a review of the current literature on the use of acellular tissue matrices in gender-affirming surgeryas well as the authors' institutionalexperience in using these products.

Stomach engineering: region-specific characterization of the decellularized porcine stomach

PurposePatients affected by microgastria, severe gastroesophageal reflux, or those who have undergone subtotal gastrectomy, have commonly described reporting dumping syndromes or other symptoms that seriously impair the quality of their life. Gastric tissue engineering may offer an alternative approach to treating these pathologies. Decellularization protocols have great potential to generate novel biomaterials for large gastric defect repair. There is an urgency to define more reliable protocols to foster clinical applications of tissue-engineered decellularized gastric grafts.MethodsIn this work, we investigated the biochemical and mechanical properties of decellularized porcine stomach tissue compared to its native counterpart. Histological and immunofluorescence analyses were performed to screen the quality of decellularized samples. Quantitative analysis was also performed to assess extracellular matrix composition. At last, we investigated the mechanical properties and cytocompatibility of the decellularized tissue compared to the native.ResultsThe optimized decellularization protocol produced efficient cell removal, highlighted in the absence of native cellular nuclei. Decellularized scaffolds preserved collagen and elastin contents, with partial loss of sulfated glycosaminoglycans. Decellularized gastric tissue revealed increased elastic modulus and strain at break during mechanical tensile tests, while ultimate tensile strength was significantly reduced. HepG2 cells were seeded on the ECM, revealing matrix cytocompatibility and the ability to support cell proliferation.ConclusionOur work reports the successful generation of acellular porcine gastric tissue able to support cell viability and proliferation of human cells.

Mucocele of the Anorectal Pouch: Mucinous Cystic Neoplasm with Low-Grade Dysplasia Simulating Low- Grade Appendiceal Mucinous Neoplasm (LAMN)

Abstract Introduction/Objective We present the second case of colonic mucocele with dysplasia. To date, only five cases of colonic mucocele have been reported, all in the setting of a pouch or bypass, with only one of them showing dysplasia. The exceptional rarity of the lesion provides unique insight into etiology of mucocele. Methods/Case Report A 44-year-old male with complex surgical history including pull-through procedure for imperforate anus at birth, and later proctectomy with end colostomy due to poor anorectal function, presented with worsening low back pain radiating down to his left leg. An abdominal CT scan revealed a large pelvic cyst, causing compressive neuropathy. Multilocular cystic mass (17.5 cm) was resected, which was partially filled with mucinous material. Mucin was not seen on the cyst surface. On microscopic examination, the cyst was largely denuded however was partially lined by markedly attenuated ano-rectal type mucosa and focally by dysplastic glandular epithelium. Similar to LAMN, pools of acellular mucin dissecting stromal tissues were noted, associated with degenerative changes, calcifications and fibrosis. No invasive carcinoma or high-grade dysplasia was seen. Given the lack of extra- cystic mucin or evidence of overt malignancy, it was reported as mucinous cystic neoplasm with uncertain malignant potential. The patient has been followed for 16 months without evidence of recurrence or peritoneal disease. Results (if a Case Study enter NA) NA Conclusion Extended stasis within a bowel segment appear to contribute to the development of mucoceles. The blind-ended anatomy of the appendix renders it highly susceptible to this phenomenon, explaining the relatively high incidence of LAMN. Conversely, such prolonged stasis rarely occurs elsewhere in colon unless a pouch or bypassed segment is surgically created, particularly placing patients with a complex surgical history at the highest risk. Therefore, close follow-up is indicated in this patient group to screen for mucocele that may progress to develop dysplasia and mucinous neoplasm.

The modern view on adipose tissue regenerative products potential in skin pathologies treatment

At this stage of regenerative medicine development, adipose tissue as a source of stem cells is the choice option due to its availability, a sufficient number of cells and the most painless sampling procedure. The high interest in this product use in scars, wounds and other dermatological diseases treatment is driven by demonstrated positive results in other medical fields.&#x0D; This review presents data on the efficacy and safety of cellular and acellular adipose tissue products use in various skin pathologies treatment. Scientific literature open electronic databases PubMed (MEDLINE), Clinical Trials, and eLIBRARY.RU were used. The literature data search was carried out using the keywords: regenerative medicine, SVF, scar, skin, dermatology, nanofat, ADSC, exosomes, lipoaspirat.&#x0D; The article presents the results and the rationale of adipose tissue regenerative products use in the most common and most significant skin diseases treatment. Cellular and acellular adipose tissue products use in dermatology and surgery is a safe and promising direction to improve skin quality. For the subsequent effective techniques application further research is needed to assess the systemic effect, as well as the development of standardized protocols for their use.

Biocompatible Human Placental Extracellular Matrix Derived Hydrogels.

Solubilizing extracellular matrix (ECM) materials and transforming them into hydrogels has expanded their potential applications both in vitro and in vivo. In this study, hydrogels are prepared by decellularization of human placental tissue using detergent and enzymes and by the subsequent creation of a homogenized acellular placental tissue powder (P-ECM). A perfusion-based decellularization approach is employed using detergent and enzymes. The P-ECM with and without gamma irradiation is then utilized to prepare P-ECM hydrogels. Physical and biological evaluations are conducted to assess the suitability of the P-ECM hydrogels for biocompatibility. The decellularized tissue has significantly reduced cellular content and retains the major ECM proteins. Increasing the concentration of P-ECM leads to improved mechanical properties of the P-ECM hydrogels. The biocompatibility of the P-ECM hydrogel is demonstrated through cell proliferation and viability assays. Notably, gamma-sterilized P-ECM does not support the formation of a stable hydrogel. Nonetheless, the use of HCl during the digestion process effectively decreases spore growth and bacterial bioburden. The study demonstrates that P-ECM hydrogels exhibit physical and biological attributes conducive to soft tissue reconstruction. These hydrogels establish a favorable microenvironment for cell growth and the need for investigating innovative sterilization methods.

Creation of a decellularized vaginal matrix from healthy human vaginal tissue for potential vagina reconstruction: experimental studies.

When a disorder causes the absence of a healthy, full-size vagina, various neovaginal creation methods are available. Sometimes dilation or stretching of the vaginal cavity is sufficient, but intestinal or dermal flap tissue is generally required. However, different inherent tissue properties cause complications. Therefore, a lost body part should be replaced with a similar material. The use of organ-specific acellular vaginal tissue carries great potential, as its similar architecture and matrix composition make it suitable for vaginal regeneration. The authors developed an optimized protocol for decellularization of healthy human vaginal tissue. Resected colpectomy tissue from 12 healthy transgender patients was used. Successful decellularization was confirmed by applying acellular criteria from in-vivo remodeling reports. Suitability as a tissue-mimicking scaffold for vaginal reconstruction was determined by visible structural features, biocompatibility during stretching, and the presence of visible collagen, elastin, laminin, and fibronectin. Histological examination confirmed the preservation of structural features, and minimal cellular residue was seen during fluorescence microscopy, DNA and RNA quantification, and fragment length examination. Biomechanical testing showed decreased peak load (55%, P <0.05), strain at rupture (23%, P <0.01), and ultimate tensile stress (55%, P <0.05) after decellularization, while the elastic modulus (68%) did not decrease significantly. Fluorescence microscopy revealed preserved Fibronectin-I/II/III and Laminin-I/II, while Collagen-I and Ficolin-2B were decreased but mostly retained. The absence of cellular residue, moderately altered biomechanical extracellular matrix properties, and mostly preserved structural proteins appear to make our decellularized human vaginal matrix a suitable tissue-mimicking scaffold for vagina transplantation when tissue survival through vascularization and innervation are accomplished in the future.

Comparative proteomic analysis of regenerative acellular matrices: The effects of tissue source and processing method.

Acellular tissue matrices are used in regenerative medicine from weak tissue re-enforcement to cosmetic augmentation. However, proteomic signatures leading to different clinical outcomes among matrices are not well understood. In an attempt to investigate the effects of tissue source and processing method, we examined by liquid chromatography tandem mass spectrometry (LC-MS/MS)the proteomic profiles of 12 regulatory agency-approved acellular matrices (AlloMax, AlloDerm, CollaMend, Heal-All, JayyaLife, ReGen, Renov, Strattice, SurgiMend, Surgisis, UniTrump and Vidasis). The compositions of acellular matrices varied greatly with the number of identified proteins ranging from 7 to 106. The content of individual proteins was between 0.0001% and 95.8% according to their abundances measured by the M/Z signal intensities. Most acellular matrices still contained numerous cellular proteins. AlloMax, AlloDerm, ReGen, Strattice, SurgiMend and Surgisis retained necessary structural and functional proteins to form the extracellular protein-protein interaction networks for cell adhesion, proliferation and tissue regeneration, whereas CollaMend, Heal-All, JayyaLife, Renov, UniTrump and Vidasis had only retained certain structural collagens. Principal component analysis showed that proteomic variations among acellular matrices were largely attributed to tissue source and processing method. Differences in proteomic profiles among acellular matrices offers insights into molecular interpretation for different clinical outcomes, and can serve as useful references for rational design of regenerative bio-scaffolds.

Hybrid Materials for Tissue Repair and Replacement: Another Frontier in Biomaterial Exploitation Focusing on Cardiovascular and Urological Fields

The main purpose of tissue engineering is to fabricate and exploit engineered constructs suitable for the effective replacement of damaged tissues and organs to perfectly integrate with the host’s organism without eliciting any adverse reaction. Ideally, autologous materials represent the best option, but they are often limited due to the low availability of compatible healthy tissues. So far, one therapeutic approach relies on the exploitation of synthetic materials as they exhibit good features in terms of impermeability, deformability, and flexibility, but present chronic risks of infections and inflammations. Alternatively, biological materials, including naturally derived ones and acellular tissue matrices of human or animal origin, can be used to induce cells growth and differentiation, which are needed for tissue regeneration; however, this kind of material lacks satisfactory mechanical resistance and reproducibility, affecting their clinical application. In order to overcome the above-mentioned limitations, hybrid materials, which can be obtained by coupling synthetic polymers and biological materials, have been investigated with the aim to improve biological compatibility and mechanical features. Currently, the interest in these materials is growing, but the ideal ones have not been found yet. The present review aims at exploring some applications of hybrid materials, with particular mention to urological and cardiovascular fields. In the first case, the efforts to find a construct that can guarantee impermeability, mechanical resistance, and patency is herein illustrated; in the second case, the search for impermeability, hemocompatibility and adequate compliance is disclosed.

Decellularized Extracellular Matrix: The Role of This Complex Biomaterial in Regeneration.

Organ transplantation is understood as a technique where an organ from a donor patient is transferred to a recipient patient. This practice gained strength in the 20th century and ensured advances in areas of knowledge such as immunology and tissue engineering. The main problems that comprise the practice of transplants involve the demand for viable organs and immunological aspects related to organ rejection. In this review, we address advances in tissue engineering for reversing the current challenges of transplants, focusing on the possible use of decellularized tissues in tissue engineering. We address the interaction of acellular tissues with immune cells, especially macrophages and stem cells, due to their potential use in regenerative medicine. Our goal is to exhibit data that demonstrate the use of decellularized tissues as alternative biomaterials that can be applied clinically as partial or complete organ substitutes.