PLGA-collagen-ECM hybrid meshes mimicking stepwise osteogenesis and their influence on the osteogenic differentiation of hMSCs

Smart composite scaffold to synchronize magnetic hyperthermia and chemotherapy for efficient breast cancer therapy

Combination of different therapies is an attractive approach for cancer therapy. However, it is a challenge to synchronize different therapies for maximization of therapeutic effects. In this work, a smart composite scaffold that could synchronize magnetic hyperthermia and chemotherapy was prepared by hybridization of magnetic Fe3O4 nanoparticles and doxorubicin (Dox)-loaded thermosensitive liposomes with biodegradable polymers. Irradiation of alternating magnetic field (AMF) could not only increase the scaffold temperature for magnetic hyperthermia but also trigger the release of Dox for chemotherapy. The two functions of magnetic hyperthermia and chemotherapy were synchronized by switching AMF on and off. The synergistic anticancer effects of the composite scaffold were confirmed by in vitro cell culture and in vivo animal experiments. The composite scaffold could efficiently eliminate breast cancer cells under AMF irradiation. Moreover, the scaffold could support proliferation and adipogenic differentiation of mesenchymal stem cells for adipose tissue reconstruction after anticancer treatment. In vivo regeneration experiments showed that the composite scaffolds could effectively maintain their structural integrity and facilitate the infiltration and proliferation of normal cells within the scaffolds. The composite scaffold possesses multi-functions and is attractive as a novel platform for efficient breast cancer therapy.

Surface Modification Progress for PLGA-Based Cell Scaffolds

Poly(lactic-glycolic acid) (PLGA) is a biocompatible bio-scaffold material, but its own hydrophobic and electrically neutral surface limits its application as a cell scaffold. Polymer materials, mimics ECM materials, and organic material have often been used as coating materials for PLGA cell scaffolds to improve the poor cell adhesion of PLGA and enhance tissue adaptation. These coating materials can be modified on the PLGA surface via simple physical or chemical methods, and coating multiple materials can simultaneously confer different functions to the PLGA scaffold; not only does this ensure stronger cell adhesion but it also modulates cell behavior and function. This approach to coating could facilitate the production of more PLGA-based cell scaffolds. This review focuses on the PLGA surface-modified materials, methods, and applications, and will provide guidance for PLGA surface modification.

Effect of Electrospun PLGA/Collagen Scaffolds on Cell Adhesion, Viability, and Collagen Release: Potential Applications in Tissue Engineering

The development of scaffolding obtained by electrospinning is widely used in tissue engineering due to porous and fibrous structures that can mimic the extracellular matrix. In this study, poly (lactic-co-glycolic acid) (PLGA)/collagen fibers were fabricated by electrospinning method and then evaluated in the cell adhesion and viability of human cervical carcinoma HeLa and NIH-3T3 fibroblast for potential application in tissue regeneration. Additionally, collagen release was assessed in NIH-3T3 fibroblasts. The fibrillar morphology of PLGA/collagen fibers was verified by scanning electron microscopy. The fiber diameter decreased in the fibers (PLGA/collagen) up to 0.6 µm. FT-IR spectroscopy and thermal analysis confirmed that both the electrospinning process and the blend with PLGA give structural stability to collagen. Incorporating collagen in the PLGA matrix promotes an increase in the material's rigidity, showing an increase in the elastic modulus (38%) and tensile strength (70%) compared to pure PLGA. PLGA and PLGA/collagen fibers were found to provide a suitable environment for the adhesion and growth of HeLa and NIH-3T3 cell lines as well as stimulate collagen release. We conclude that these scaffolds could be very effective as biocompatible materials for extracellular matrix regeneration, suggesting their potential applications in tissue bioengineering.

Comparison of the enhanced attachment and proliferation of the human mesenchymal stem cells on the biomimetic nanopatterned surfaces of zein, silk fibroin, and gelatin

Natural proteins have been reported to positively affect the attachment and proliferation of cells. For the first time, zein, a plant protein, was utilized to make patterned surface mimicking the extracellular matrix to assist the attachment and proliferation of stem cells. Zein would promote the attachment and proliferation of the stem cells more than 10 times of that of gelatin and silk fibroin, respectively, which are popular protein selections for the formation of the biomaterial scaffolds. The more the surface was covered by zein, the more the stem cell grown. It was revealed that the stem cells would grow and stretch in the direction of the patterns, and the stem cells preferred to grow in the grooves in the size of 8 μm, that was similar to the size of the stem cells, rather than the size larger or smaller than that of the cells, such as 50 and 2 μm. It was concluded that zein is a better choice than silk fibroin and gelatin with highly potential for the formation of patterned surface and structure as the biomaterial scaffolds for stem cell therapy.

Composite Scaffolds of Gelatin and Fe3 O4 Nanoparticles for Magnetic Hyperthermia-Based Breast Cancer Treatment and Adipose Tissue Regeneration

Postsurgical treatment of breast cancer remains a challenge with regard to killing residual cancer cells and regenerating breast defects. To prepare composite scaffolds for postoperative use, gelatin is chemically modified with folic acid (FA) and used for hybridization with citrate-modified Fe₃ O₄ nanoparticles (Fe₃ O₄ -citrate NPs) to fabricate Fe₃ O₄ /gelatin composite scaffolds which pore structures are controlled by free ice microparticles. The composite scaffolds have large spherical pores that are interconnected to facilitate cell entry and exit. The FA-functionalized composite scaffolds have the ability to capture breast cancer cells. The Fe₃ O₄ /gelatin composite scaffolds possess a high capacity for magnetic-thermal conversion to ablate breast cancer cells during alternating magnetic field (AMF) irradiation. In addition, the composite scaffolds facilitate the growth and adipogenesis of mesenchymal stem cells. The composite scaffolds have multiple functions for eradication of residual cancer cells under AMF irradiation and for regeneration of resected adipose tissue when AMF is off.

Constructing ECM-like Structure on the Plasma Membrane via Peptide Assembly to Regulate the Cellular Response

This feature article introduces the design of self-assembling peptides that serve as the basic building blocks for the construction of extracellular matrix (ECM)-like structure in the vicinity of the plasma membrane. By covalently conjugating a bioactive motif, such as membrane protein binding ligand or enzymatic responsive building block, with a self-assembling motif, especially the aromatic peptide, a self-assembling peptide that retains bioactivity is obtained. Instructed by the target membrane protein or enzyme, the bioactive peptides self-assemble into ECM-like structure exerting various stimuli to regulate the cellular response via intracellular signaling, especially mechanotransduction. By briefly summarizing the properties and applications (e.g., wound healing, controlling cell motility and cell fate) of these peptides, we intend to illustrate the basic requirements and promises of the peptide assembly as a true bottom-up approach in the construction of artificial ECM.

Chitosan and Collagen-Based Materials Enriched with Curcumin (Curcuma longa): Rheological and Morphological Characterization

In this study, chitosan and collagen (Ch: Col)-based materials containing curcumin (Cur) as a bioactive compound were developed for wound-healing purposes. The effects of incorporating curcumin and increasing its concentration on both the rheological properties of the formed solutions and the morphological and thermal properties of the three-dimensional scaffolds obtained from them were evaluated. Rheology showed that the presence of curcumin resulted in solutions with a solid-like behavior (G’ > G″), higher collagen denaturation temperatures, and higher viscosities, favoring their use as biomaterials for wound healing. A greater cross-linking effect was observed at higher curcumin concentrations, possibly between the amino groups from both polymers and the hydroxyl and keto groups from the polyphenol. Such cross-linking was responsible for the delay in the onset of degradation of the scaffolds by 5 °C, as revealed by thermogravimetric analysis. Moreover, the pore diameter distribution profile of the scaffolds changed with increasing curcumin concentration; a greater number of pores with diameters between 40 and 60 µm was observed for the scaffold with the highest curcumin content (50 mg), which would be the most suitable for the proposed application. Thus, the materials developed in this study are presented as promising biomaterials for their biological evaluation in tissue regeneration.

PLGA-collagen-BPNS Bifunctional composite mesh for photothermal therapy of melanoma and skin tissue engineering

The treatment of melanoma requires not only the elimination of skin cancer cells but also skin regeneration to heal defects. To achieve this goal, a bifunctional composite scaffold of poly(DL-lactic-co-glycolic acid) (PLGA), collagen and black phosphorus nanosheets (BPNSs) was prepared by hybridizing a BPNS-embedded collagen sponge with a PLGA knitted mesh. The composite mesh increased the temperature under near-infrared laser irradiation. The incorporation of BPNSs provided the PLGA-collagen-BPNS composite mesh with excellent photothermal properties for the photothermal ablation of melanoma cells both in vitro and in vivo. The PLGA-collagen-BPNS composite mesh had high mechanical strength for easy handling. The PLGA-collagen-BPNS composite mesh facilitated the proliferation of fibroblasts, promoted the expression of angiogenesis-related genes and the genes of components of the extracellular matrix for skin tissue regeneration. The high mechanical strength, photothermal ablation capability and skin tissue regeneration effects demonstrate that the bifunctional PLGA-collagen-BPNS composite mesh is a versatile and effective platform for the treatment of melanoma and the regeneration of skin defects.

Interconnected collagen porous scaffolds prepared with sacrificial PLGA sponge templates for cartilage tissue engineering

Interconnected pore structures of scaffolds are important to control the cell functions for cartilage tissue engineering. In this study, collagen scaffolds with interconnected pore structures were prepared using poly(D,L-lactide-co-glycolide) (PLGA) sponges as sacrificial templates. Six types of PLGA sponges of different pore sizes and porosities were prepared by the solvent casting/particulate leaching method and used to regulate the interconnectivity of the collagen scaffolds. The integral and continuous templating structure of PLGA sponges generated well-interconnected pore structures in the collagen scaffolds. Bovine articular chondrocytes cultured in collagen scaffolds showed homogenous distribution, fast proliferation, high expression of cartilaginous genes and high secretion of cartilaginous extracellular matrix. In particular, the collagen scaffold templated by the PLGA sacrificial sponge that was prepared with a high weight ratio of PLGA and large salt particulates showed the most promotive effect on cartilage tissue formation. The interconnected pore structure facilitated cell distribution, cell-cell interaction and cartilage tissue regeneration.

Purification of Colon Carcinoma Cells from Primary Colon Tumor Using a Filtration Method via Porous Polymeric Filters

Cancer stem cells (CSCs) or cancer-initiating cells (CICs) are key factors for tumor generation and metastasis. We investigated a filtration method to enhance CSCs (CICs) from colon carcinoma HT-29 cells and primary colon carcinoma cells derived from patient colon tumors using poly(lactide-co-glycolic acid)/silk screen (PLGA/SK) filters. The colon carcinoma cell solutions were permeated via porous filters to obtain a permeation solution. Then, the cell cultivation media were permeated via the filters to obtain the recovered solution, where the colon carcinoma cells that adhered to the filters were washed off into the recovered solution. Subsequently, the filters were incubated in the culture media to obtain the migrated cells via the filters. Colon carcinoma HT-29 cells with high tumorigenicity, which might be CSCs (CICs), were enhanced in the cells in the recovered solution and in the migrated cells based on the CSC (CIC) marker expression, colony-forming unit assay, and carcinoembryonic antigen (CEA) production. Although primary colon carcinoma cells isolated from colon tumor tissues contained fibroblast-like cells, the primary colon carcinoma cells were purified from fibroblast-like cells by filtration through PLGA/SK filters, indicating that the filtration method is effective in purifying primary colon carcinoma cells.

Employing Extracellular Matrix-Based Tissue Engineering Strategies for Age-Dependent Tissue Degenerations

Tissues and organs are not composed of solely cellular components; instead, they converge with an extracellular matrix (ECM). The composition and function of the ECM differ depending on tissue types. The ECM provides a microenvironment that is essential for cellular functionality and regulation. However, during aging, the ECM undergoes significant changes along with the cellular components. The ECM constituents are over- or down-expressed, degraded, and deformed in senescence cells. ECM aging contributes to tissue dysfunction and failure of stem cell maintenance. Aging is the primary risk factor for prevalent diseases, and ECM aging is directly or indirectly correlated to it. Hence, rejuvenation strategies are necessitated to treat various age-associated symptoms. Recent rejuvenation strategies focus on the ECM as the basic biomaterial for regenerative therapies, such as tissue engineering. Modified and decellularized ECMs can be used to substitute aged ECMs and cell niches for culturing engineered tissues. Various tissue engineering approaches, including three-dimensional bioprinting, enable cell delivery and the fabrication of transplantable engineered tissues by employing ECM-based biomaterials.

Biomaterials for Soft Tissue Repair and Regeneration: A Focus on Italian Research in the Field

Tissue repair and regeneration is an interdisciplinary field focusing on developing bioactive substitutes aimed at restoring pristine functions of damaged, diseased tissues. Biomaterials, intended as those materials compatible with living tissues after in vivo administration, play a pivotal role in this area and they have been successfully studied and developed for several years. Namely, the researches focus on improving bio-inert biomaterials that well integrate in living tissues with no or minimal tissue response, or bioactive materials that influence biological response, stimulating new tissue re-growth. This review aims to gather and introduce, in the context of Italian scientific community, cutting-edge advancements in biomaterial science applied to tissue repair and regeneration. After introducing tissue repair and regeneration, the review focuses on biodegradable and biocompatible biomaterials such as collagen, polysaccharides, silk proteins, polyesters and their derivatives, characterized by the most promising outputs in biomedical science. Attention is pointed out also to those biomaterials exerting peculiar activities, e.g., antibacterial. The regulatory frame applied to pre-clinical and early clinical studies is also outlined by distinguishing between Advanced Therapy Medicinal Products and Medical Devices.

Improvement of the Wound-Healing Process by Curcumin-Loaded Chitosan/Collagen Blend Electrospun Nanofibers: In Vitro and In Vivo Studies

Chronic wounds have become a major health problem worldwide. Curcumin (Cur), with strong anti-inflammatory and anti-infective properties, is introduced as a unique molecule for wound dressing applications. In the present study, Cur-loaded chitosan/poly(ethylene oxide)/collagen (Cho/PEO/Col) nanofibers were developed for wound dressing applications by the blend-electrospinning process. Structural, mechanical, and biological properties of nanofibers were evaluated using SEM, FTIR, tensile testing, in vitro release study, Alamar blue cytotoxicity assay, and in vivo study in a rat model. According to the results, Cur was successfully released up to 3 days without any significant cytotoxicity of the above hybrid to human dermal fibroblasts. In vivo studies on full-thickness wounds in the rat model indicated significant improvement in the mean wound area closure by applying Cur-loaded Cho/PEO/Col nanofibers. The electrospun Cho/PEO/Col nanofibers loaded with Cur could be considered as a promising type of wound dressing in the wound-healing process.

Composite scaffolds of black phosphorus nanosheets and gelatin with controlled pore structures for photothermal cancer therapy and adipose tissue engineering

Breast cancer treatment needs to eradicate cancer cells and restore breast defects after surgical intervention. Herein, bifunctional composite scaffolds of black phosphorus nanosheets (BPNSs) and gelatin were designed to kill breast cancer cells and induce adipose tissue reconstruction. The composite scaffolds were prepared by hybridizing photothermal BPNSs with porous gelatin matrices by adding pre-prepared ice particles to precisely adjust their pore structures. The composite scaffolds had large, well-interconnected spherical pores, which allowed cell migration and infiltration. Hybridization with BPNSs increased the compression strength of the scaffolds. The composite scaffolds possessed a high photothermal conversion capacity that was dependent on the amount of BPNSs. The composite scaffold with a high amount of BPNSs could completely kill breast cancer cells in vitro and in vivo under laser irradiation. Moreover, cell culture and animal experiment results showed that the composite scaffolds promoted lipid oil droplet formation and upregulated the expression of adipogenesis-related genes when hMSCs were cultured in the scaffolds. The composite scaffolds could offer a facile platform to exert anticancer effects against breast cancer cells and promote the reconstruction of adipose tissue.

Enrichment of cancer-initiating cells from colon cancer cells through porous polymeric membranes by a membrane filtration method

Cancer-initiating cells (CICs) or cancer stem cells (CSCs) are primarily responsible for tumor initiation, growth, and metastasis and represent a few percent of the total tumor cell population. We designed a membrane filtration protocol to enrich CICs (CSCs) from the LoVo colon cancer cell line via nylon mesh filter membranes with 11 and 20 μm pore sizes and poly(lactide-co-glycolic acid)/silk screen (PLGA/silk screen) porous membranes (pore sizes of 20-30 μm). The colon cancer cell solution was filtered through the membranes to obtain a permeate solution. Subsequently, the cell culture medium was filtered through the membranes to collect the recovery solution where the cells attached to the membranes were rinsed off into the recovery solution. Then, the membranes were cultivated in the cultivation medium to collect the migrated cells from the membranes. The cells migrated from any membrane had higher expression of the CSC surface markers CD44 and CD133, had higher colony formation levels, and produced more carcinoembryonic antigen (CEA) than the colon cancer cells cultivated on conventional tissue culture plates (control). We established a method to enrich the CICs (CSCs) of colon cancer cells from migrated cells through porous polymeric membranes by the membrane filtration protocol developed in this study.

Demineralized bone matrix scaffold modified with mRNA derived from osteogenically pre-differentiated MSCs improves bone repair

Gene therapy based on mRNA provides a promising approach for bone regeneration. Quick mRNA translation and controlled protein production could be earned by implantation of mRNA-activated scaffold in bone remodeling region. Furthermore, the expression levels of osteogenic-related mRNA in the cytoplasm of osteogenically pre-differentiated mesenchymal stem cells (MSCs) were high and the expression levels were different at different stages of osteogenically differentiated MSCs. This study intended to investigate the effect of osteoinductive-mRNAs (Oi-mRNAs), derived from osteogenically pre-differentiated MSCs at various stages (Day 1 (Oi1-mRNA), Day 3 (Oi3-mRNA), Day 7 (Oi7-mRNA), Day 14 (Oi14-mRNA) and Day 21 (Oi21-mRNA), respectively), on the osteogenic differentiation of MSCs. Further, the Oi-mRNAs combined with cationic polymer polyethylenimine (PEI) were loaded onto demineralized bone matrix (DBM) scaffold (Oi-mRNA/DBM). The results revealed that the Oi1-mRNA, Oi3-mRNA and Oi21-mRNA had no obvious effect on the osteogenic differentiation of MSCs, while the Oi7-mRNA increased the expression of alkaline phosphatase (ALP) and the Oi14-mRNA significantly promoted the expression of osteocalcin (OC) and osteopontin (OPN), and calcium deposition. In addition, the Oi14-mRNA/DBM scaffold could significantly enhance extracellular matrix (ECM) secretion and new collagen formation of MSCs. After being implanted into rat critical-sized cranium defect model, the Oi14-mRNA/DBM scaffold could promote the infiltration of cells and repair of bone defect in vivo. The DBM scaffold loaded with mRNA encoding osteoinductive protein may provide a powerful tool for bone defect repair.

ECM scaffolds mimicking extracellular matrices of endochondral ossification for the regulation of mesenchymal stem cell differentiation

Endochondral ossification (ECO) is an important process of bone tissue development. During ECO, extracellular matrices (ECMs) are essential factors to control cell functions and induce bone regeneration. However, the exact role of ECO ECMs on stem cell differentiation remains elusive. In this study, ECM scaffolds were prepared to mimic the ECO-related ECM microenvironments and their effects on stem cell differentiation were compared. Four types of ECM scaffolds mimicking the ECMs of stem cells (SC), chondrogenic (CH), hypertrophic (HY) and osteogenic (OS) stages were prepared by controlling differentiation of human bone marrow-derived mesenchymal stem cells (MSCs) at different stages. Composition of the ECM scaffolds was dependent on the differentiation stage of MSCs. They showed different influence on osteogenic differentiation of MSCs. HY ECM scaffold had the most promotive effect on osteogenic differentiation of MSCs. CH ECM and OS ECM scaffolds showed moderate effect, while SC ECM scaffold had the lowest effect on osteogenic differentiation of MSCs. Their effects on chondrogenic or adipogenic differentiation were not significantly different. The results suggested that the engineered HY ECM scaffold had superior effect for osteogenic differentiation of MSCs. Statement of significance ECM scaffolds mimicking endochondral ossification-related ECM microenvironments are pivotal for elucidation of their roles in regulation of stem cell functions and bone tissue regeneration. This study offers a method to prepare ECM scaffolds that mimic the ECMs from cells at hypertrophic, osteogenic, chondrogenic and stem cell stages. Their composition and impacts on osteogenic differentiation of MSCs were compared. The hypertrophic ECM scaffold had the highest promotive effect on osteogenic differentiation of MSCs. The results advance our understanding about the role of ECO ECMs in regulation of stem cell functions and provide perspective for bone defect repair strategies.