A three dimensional in vivo model of breast cancer using a thermosensitive chitosan-based hydrogel and 4 T1 cell line in Balb/c

Recent advances in hydrogels applications for tissue engineering and clinical trials

Hydrogels are biomolecules made of artificial and natural polymers. Their quasi-three-dimensional structure has created unique features. They are very hydrophilic, and in addition to the high inflation rate, they also have excellent water maintenance capacity, biodegradability, biocompatibility, and strong mechanical properties. These properties are used in many tissue engineering applications. All these features have made these scaffolds widely used as attractive structures in the world of tissue engineering and regeneration medicine. In addition to research, scaffolds entered the field of medicine and are expected to play a significant role in the repair of many tissues in the future. This study aims to review the various polymers involved in hydrogel fabrication and their application in the repair of diverse tissues and clinical trials.

Magnesium-oxide-enhanced bone regeneration: 3D-printing of gelatin-coated composite scaffolds with sustained Rosuvastatin release

Critical-size bone defects are one of the main challenges in bone tissue regeneration that determines the need to use angiogenic and osteogenic agents. Rosuvastatin (RSV) is a class of cholesterol-lowering drugs with osteogenic potential. Magnesium oxide (MgO) is an angiogenesis component affecting apatite formation. This study aims to evaluate 3D-printed Polycaprolactone/β-tricalcium phosphate/nano-hydroxyapatite/ MgO (PCL/β-TCP/nHA/MgO) scaffolds as a carrier for MgO and RSV in bone regeneration. For this purpose, PCL/β-TCP/nHA/MgO scaffolds were fabricated with a 3D-printing method and coated with gelatin and RSV. The biocompatibility and osteogenicity of scaffolds were examined with MTT, ALP, and Alizarin red staining. Finally, the scaffolds were implanted in a bone defect of rat's calvaria, and tissue regeneration was investigated after 3 months. Our results showed that the simultaneous presence of RSV and MgO improved biocompatibility, wettability, degradation rate, and ALP activity but decreased mechanical strength. PCL/β-TCP/nHA/MgO/gelatin-RSV scaffolds produced sustained release of MgO and RSV within 30 days. CT images showed that PCL/β-TCP/nHA/MgO/gelatin-RSV scaffolds filled approximately 86.83 + 4.9 % of the defects within 3 months and improved angiogenesis, woven bone, and osteogenic genes expression. These results indicate the potential of PCL/β-TCP/nHA/MgO/gelatin-RSV scaffolds as a promising tool for bone regeneration and clinical trials.

Tissue Engineering Scaffolds Loaded With a Variety of Plant Extracts: Novel Model in Breast Cancer Therapy

Despite recent improvements in detecting and managing breast cancer (BC), it continues to be a major worldwide health concern that annually affects millions of people. Exploring the anti-BC potentials of natural compounds has received a lot of scientific attention due to their multi-target mode of action and good safety profiles because of these unmet needs. Drugs made from herbs are secure and have a lot fewer negative effects than those made from synthetic materials. Early stage patients benefit from breast-conserving surgery, but the risk of local recurrence remains, necessitating implanted scaffolds. These scaffolds provide residual cancer cell killing and tailored drug delivery. This review looks at plant extract-infused tissue engineering scaffolds, which provide a novel approach to treating BC. By offering patient individualized, safer treatments, these scaffolds could completely change how BC is treated.

Cell-loaded genipin cross-linked collagen/gelatin skin substitute adorned with zinc-doped bioactive glass-ceramic for cutaneous wound regeneration

An optimal tissue-engineered dermal substitute should possess biocompatibility and cell adhesion conduction to facilitate fibroblast and keratinocyte infiltration and proliferation, as well as angiogenesis potential to escalate wound healing. Zinc was doped to bioactive glass-ceramic (Zn-BGC) to promote biocompatibility and angiogenesis properties. Zn-BGC was then incorporated into a collagen (Col) and gelatin (Gel) porous scaffold. The bioactive porous bionanocomposite exhibited biocompatibility along with improved cell attachment and proliferation. Scaffolds including Col-Gel/Zn-BGC with or without mouse embryonic fibroblasts were applied on full-thickness skin wounds on the BALB/c mice to assess their wound healing potential in vivo. The results indicated that the biodegradation rate of the Col-Gel/Zn-BGC nanocomposites was comparable to the rate of skin tissue regeneration in vivo. Macroscopic wound healing results showed that Col-Gel/Zn-BGC loaded with mouse embryonic fibroblast possesses the smallest wound size, indicating the fastest healing process. Histopathological evaluations displayed that the optimal wound regeneration was observed in Col-Gel/Zn-BGC nanocomposites loaded with mouse embryonic fibroblasts indicated by epithelialization and angiogenesis; besides the number of fibroblasts and hair follicles was increased. The bioactive nanocomposite scaffold of Col-Gel containing Zn-BGC nanoparticles loaded with mouse embryonic fibroblasts can be employed as a desirable skin substitute to ameliorate cutaneous wound regeneration.

A Novel Three-Dimensional Follicle Culture System Decreases Oxidative Stress and Promotes the Prolonged Culture of Human Granulosa Cells

Tissue engineering advancements have made it possible to modify biomaterials to reconstruct a similar three-dimensional structure of the extracellular matrix (ECM) for follicle development and to supply the required biological signals. We postulated that an artificial polysaccharide hydrogel modified with an ECM mimetic peptide may produce efficient irritation signals by binding to specific integrins providing a suitable environment for follicular development and influencing the behavior of human granulosa cells (hGCs). Laminin, an important component of the extracellular matrix, can modulate hGCs and oocyte growth. Specifically, follicles of mice were randomly divided into two-dimensional (2D) and three-dimensional (3D) culture systems established by a hydrogel modified with RGD or laminin mimetic peptides (IKVAV and YIGSR) and RGD (IYR). Our results showed that 3D cultured systems significantly improved follicle survival, growth, and viability. IYR peptides enhanced the oocyte meiosis competence. Additionally, we explored the effect of 3D culture on hGCs, which improved hGCs viability, increased the proportion of S- and G2/M-phase cells, and inhibited cell apoptosis of hGCs. On days 1 and 2, the secretion of progesterone was reduced in 3D-cultured hGCs. Notably, 3D-cultured hGCs exhibited delayed senescence, decreased oxidative stress, and elevated mitochondrial membrane potential. Moreover, the expression levels of cumulus expansion-related genes (COX2, HAS2, and PTX3) and integrin α6β1 were upregulated in 3D-cultured hGCs. In conclusion, a 3D culture utilizing hydrogels modified with Laminin-mimetic peptides can provide a durable physical environment suitable for follicular development. The laminin-mimetic peptides may regulate the biological activity of hGCs by attaching to the integrin α6β1.

Exosomes and exosome-loaded scaffolds: Characterization and application in modern regenerative medicine

Exosomes (EXOs) are extracellular vesicles derived from the endosome. These heterogeneous nanoparticles (30-150 nm) are secreted from various cells and play important biological roles in intercellular communication. EXOs have received much attention for application in regenerative therapies and tissue repair due to their stability, biosafety, and functional versatility. However, in their free forms, "EXOs have poor bioavailability" at the site of action and are devoid of controlled-release mechanisms. These issues have been largely remedied by scaffolding EXOs with appropriate biomaterials such as hydrogels to create EXOs -loaded scaffold (ELS). These biomaterial-based scaffolds can be rationally designed and functionalized to enhance various aspects of ELS including bioavailability, biocompatibility, and loading/release control. Additionally, the ELS are superior to free EXOs due to reduced injection-related side effects. This review article provides a comprehensive and updated account of EXOs and ELS isolation, characterization, and application in regenerative medicine with a focus on soft tissue repair. We also offer insights into the advantages of ELS therapy compared to stem cell therapy towards application in wound healing, cardiac and bone repair. ELS promotes cell migration to the scaffold and will cause better homing of exosomes. Different types of scaffolds are made and each one can be modified based on the repair in the target tissues so that the reactions between the scaffold and exosome take place properly and effective signals are created for tissue repair.

Monitor Tumor pHe and Response Longitudinally during Treatment Using CEST MRI-Detectable Alginate Microbeads

Imaging pHe of the tumor microenvironment has paramount importance for characterizing aggressive, invasive tumors, as well as therapeutic responses. Here, a robust approach to image pH changes in the tumor microenvironment longitudinally and during sodium bicarbonate treatment was reported. The pH-sensing microbeads were designed and prepared based on materials approved for clinical use, i.e., alginate microbead-containing computed tomography (CT) contrast-agent (iopamidol)-loaded liposomes (Iop-lipobeads). This Iop-lipobead prepared using a customized microfluidic device generated a CEST contrast of 10.6% at 4.2 ppm at pH 7.0, which was stable for 20 days in vitro. The CEST contrast decreased by 11.8% when the pH decreased from 7.0 to 6.5 in vitro. Optimized Iop-lipobeads next to tumors showed a significant increase of 19.7 ± 6.1% (p < 0.01) in CEST contrast at 4.2 ppm during the first 3 days of treatment and decreased to 15.2 ± 4.8% when treatment stopped. Notably, percentage changes in Iop-lipobeads were higher than that of amide CEST (11.7% and 9.1%) in tumors during and after treatment. These findings demonstrated that the Iop-lipobead could provide an independent and sensitive assessment of the pHe changes for a noninvasive and longitudinal monitoring of the treatment effects using multiple CEST contrast.

In situ Hydrogels for Effective Treatment of Cancer: Strategies and Polymers Used

Cancer is a worldwide health ailment with no known boundaries in terms of mortality and occurrence rates, thus is one of the biggest threats to humankind. Hence, there is an absolute need to develop novel therapeutics to bridge the infirmities associated with chemotherapy and conventional surgical methodologies including impairment of normal tissue, compromised drug efficiency and an escalation in side effects. In lieu of this, there's been a surge in curiosity towards development of injectable hydrogels for cancer therapy because local administration of the active pharmaceutical agent offers encouraging advantages such as providing higher effective dose at target site, prolonged retention time of drug, ease of administration, mitigation of dose in vivo ,improved patient compliance. Furthermore, due to its biocompatible nature such systems can significantly reduce the side effects that occur on long-term exposure to chemotherapy. The present review details the most recent advancements in in-situ gel forming polymers (natural and synthetic), polymeric cross-linking methodologies and in-situ gelling mechanisms, focusing on their clinical benefits in cancer therapy.

Cell loaded hydrogel containing Ag-doped bioactive glass-ceramic nanoparticles as skin substitute: Antibacterial properties, immune response, and scarless cutaneous wound regeneration

An ideal tissue-engineered dermal substitute should possess angiogenesis potential to promote wound healing, antibacterial activity to relieve the bacterial burden on skin, as well as sufficient porosity for air and moisture exchange. In light of this, a glass-ceramic (GC) has been incorporated into chitosan and gelatin electrospun nanofibers (240-360 nm), which MEFs were loaded on it for healing acceleration. The GC was doped with silver to improve the antibacterial activity. The bioactive nanofibrous scaffolds demonstrated antibacterial and superior antibiofilm activities against Gram-negative and Gram-positive bacteria. The nanofibrous scaffolds were biocompatible, hemocompatible, and promoted cell attachment and proliferation. Nanofibrous skin substitutes with or without Ag-doped GC nanoparticles did not induce an inflammatory response and attenuated LPS-induced interleukin-6 release by dendritic cells. The rate of biodegradation of the nanocomposite was similar to the rate of skin regeneration under in vivo conditions. Histopathological evaluation of full-thickness excisional wounds in BALB/c mice treated with mouse embryonic fibroblasts-loaded nanofibrous scaffolds showed enhanced angiogenesis, and collagen synthesis as well as regeneration of the sebaceous glands and hair follicles in vivo.

Polymeric Hydrogels for In Vitro 3D Ovarian Cancer Modeling

Ovarian cancer (OC) grows and interacts constantly with a complex microenvironment, in which immune cells, fibroblasts, blood vessels, signal molecules and the extracellular matrix (ECM) coexist. This heterogeneous environment provides structural and biochemical support to the surrounding cells and undergoes constant and dynamic remodeling that actively promotes tumor initiation, progression, and metastasis. Despite the fact that traditional 2D cell culture systems have led to relevant medical advances in cancer research, 3D cell culture models could open new possibilities for the development of an in vitro tumor microenvironment more closely reproducing that observed in vivo. The implementation of materials science and technology into cancer research has enabled significant progress in the study of cancer progression and drug screening, through the development of polymeric scaffold-based 3D models closely recapitulating the physiopathological features of native tumor tissue. This article provides an overview of state-of-the-art in vitro tumor models with a particular focus on 3D OC cell culture in pre-clinical studies. The most representative OC models described in the literature are presented with a focus on hydrogel-based scaffolds, which guarantee soft tissue-like physical properties as well as a suitable 3D microenvironment for cell growth. Hydrogel-forming polymers of either natural or synthetic origin investigated in this context are described by highlighting their source of extraction, physical-chemical properties, and application for 3D ovarian cancer cell culture.

A comparative study of the effects of crab derived exosomes and doxorubicin in 2 & 3-dimensional in vivo models of breast cancer

INTRODUCTION

Using tissue engineering and modifying the tumor microenvironment, three-dimensional (3D) in vitro and in vivo cancer modeling can be performed with appropriate similarity to native. Exosomes derived from different sources have recently been used in cancer studies due to their anticancer effects. In this study, the effect of crab derived exosomes in 2 & 3-dimensional (2& 3D) in vivo models of breast cancer (BC) were investigated and compared with the doxorubicin (DOX).

METHODS

2D and 3D models of BC were induced using the chitosan/β-glycerol phosphate hydrogel (Ch/β-GP) and 1 × 10⁶ 4T1 cells in the female mice aged 6-8 weeks. 1 mg/ml exosome and 5 mg/kg DOX were injected by intratumoral (IT), intravenous (IV), and intraperitoneal (IP) methods into mice on day 9, 13, and 17 with and without hydrogel as a drug delivery system. After 21 days, the mice were sacrificed, and the tissues (lung, liver, and tumor) were removed. The weight and size of the tumor were measured. Real-time PCR assessed changes of VEGF, Bcl2, and P53 genes expression levels. Nitric oxide (NO) secretion from the cancer 3D model was evaluated by Griess assay.

RESULTS AND CONCLUSION

Based on the results, the size and weight of tumors in treated groups with exosomes and DOX were reduced significantly (P ≤ 0.001, P ≤ 0.002, P ≤ 0.02) in 2D and 3D models. Changes in VEGF, Bcl2 and P53 gene expression levels were less in the 3D model than in the 2D model. Drug delivery with hydrogel increased tumor inhibition compared to drug injection without hydrogel. Decreased NO secretion was observed in all treatment groups compared to the control group (untreated). Crab exosomes showed anti cancer effects on 2&3D models of BC. 3D model of BC showed greater drug resistance than the 2D model after treating with crab derived exosomes and DOX. 3D model of BC mimics native tumor better than 2D and can be used in cancer studies and for drug screening with greater confidence than 2D model. Also, the use of slow release drug delivery system reduced drug resistance in both models.

Chitosan: A versatile bio-platform for breast cancer theranostics

Breast cancer is considered one of the utmost neoplastic diseases globally, with a high death rate of patients. Over the last decades, many approaches have been studied to early diagnose and treat it, such as chemotherapy, hormone therapy, immunotherapy, and MRI and biomarker tests; do not show the optimal efficacy. These existing approaches are accompanied by severe side effects, thus recognizing these challenges, a great effort has been done to find out the new remedies for breast cancer. Main finding: Nanotechnology opened a new horizon to the treatment of breast cancer. Many nanoparticulate platforms for the diagnosis of involved biomarkers and delivering antineoplastic drugs are under either clinical trials or just approved by the Food and Drug Administration (FDA). It is well known that natural phytochemicals are successfully useful to treat breast cancer because these natural compounds are safer, available, cheaper, and have less toxic effects. Chitosan is a biocompatible and biodegradable polymer. Further, it has outstanding features, like chemical functional groups that can easily modify our interest with an exceptional choice of promising applications. Abundant studies were directed to assess the chitosan derivative-based nanoformulation's abilities in delivering varieties of drugs. However, the role of chitosan in diagnostics and theranostics not be obligated. The present servey will discuss the application of chitosan as an anticancer drug carrier such as tamoxifen, doxorubicin, paclitaxel, docetaxel, etc. and also, its role as a theranostics (i.e. photo-responsive and thermo-responsive) moieties. The therapeutic and theranostic potential of chitosan in cancer is promising and it seems that to have a good potential to get to the clinic.

Functional survey of decellularized tissues transplantation for infertile females

Numbers of women worldwide face infertility, which will have a significant impact on a couple's life. As a result, assisting with the treatment of these individuals is seen as a critical step. Successful births following uterus and ovary donation have been reported in recent. When immunosuppressive drugs are used in patients who receive donated tissues, there are always problems with the drugs' side effects. In recent years, tissue engineering has mainly been successful in treating infertility using decellularization techniques. Engineered uterus and ovary prevent immunological reactions and do not require immunosuppressive drugs. The most important aspect of using decellularized tissue is its proper function after transplantation. These tissues must be able to produce follicles, secrete hormones and cause pregnancy. This study aimed to investigate research on decellularized tissues and transplanted into the female reproductive system. In this study, just tissues that, after transplantation, have the proper function for fertility were investigated.

Using Chitosan or Chitosan Derivatives in Cancer Therapy

Cancer is one of the major causes of death worldwide. Chemotherapeutic drugs have become a popular choice as anticancer agents. Despite the therapeutic benefits of chemotherapeutic drugs, patients often experience side effects and drug resistance. Biopolymers could be used to overcome some of the limitations of chemotherapeutic drugs, as well as be used either as anticancer agents or drug delivery vehicles. Chitosan is a biocompatible polymer derived from chitin. Chitosan, chitosan derivatives, or chitosan nanoparticles have shown their promise as an anticancer agent. Additionally, functionally modified chitosan can be used to deliver nucleic acids, chemotherapeutic drugs, and anticancer agents. More importantly, chitosan-based drug delivery systems improved the efficacy, potency, cytotoxicity, or biocompatibility of these anticancer agents. In this review, we will investigate the properties of chitosan and chemically tuned chitosan derivatives, and their application in cancer therapy.

The effect of Scrophularia striata on cell attachment and biocompatibility of decellularized bovine pericardia

Since using tissue transplantation has faced limitations all over the world, regenerative medicine has introduced decellularized tissues as natural scaffolds and researchers are trying to improve their efficiency and function. In this study, to increase cell attachment and ultimately cell proliferation on decellularized bovine pericardia, scrophularia striata extract was used. Scrophularia striata is an Iranian traditional medicinal plant. For this aim after decellularization of bovine pericardium and analysis of its morphology, it was incubated in scrophularia striata solution. Next, isolated human adipose-derived mesenchymal stem cells were cultured on the tissue. Finally, MTT assay, nitric oxide assay, and scanning electron microscopy observation were performed. MTT showed an increase in cell survival after treating the tissue with the plant extract after 48 h in a dose dependent manner significantly. The survival of cells in 0.5%, 2.5%, and 5% groups was about 5, 10 and 15 folds higher in comparison to control groups, respectively. Additionally, nitric oxide secretion in 2.5% and 5% samples was three and five folds higher than that in control group, respectively. Moreover, SEM observation indicated an impressive and dose-dependent effect of using Scrophularia striata on tissue biocompatibility. The results of this study showed that using Scrophularia striata increased cell viability and cell attachment on decellularized pericardia which could pave the way for the use of natural extracts of medicinal plants to reduce unwanted effects and make desired changes in decellularized tissues.

3D Modeling of Epithelial Tumors-The Synergy between Materials Engineering, 3D Bioprinting, High-Content Imaging, and Nanotechnology

The current statistics on cancer show that 90% of all human cancers originate from epithelial cells. Breast and prostate cancer are examples of common tumors of epithelial origin that would benefit from improved drug treatment strategies. About 90% of preclinically approved drugs fail in clinical trials, partially due to the use of too simplified in vitro models and a lack of mimicking the tumor microenvironment in drug efficacy testing. This review focuses on the origin and mechanism of epithelial cancers, followed by experimental models designed to recapitulate the epithelial cancer structure and microenvironment, such as 2D and 3D cell culture models and animal models. A specific focus is put on novel technologies for cell culture of spheroids, organoids, and 3D-printed tissue-like models utilizing biomaterials of natural or synthetic origins. Further emphasis is laid on high-content imaging technologies that are used in the field to visualize in vitro models and their morphology. The associated technological advancements and challenges are also discussed. Finally, the review gives an insight into the potential of exploiting nanotechnological approaches in epithelial cancer research both as tools in tumor modeling and how they can be utilized for the development of nanotherapeutics.