3D Cell Culture Research Articles

A Novel Hydrogel Sponge for Three-Dimensional Cell Culture

Background/Objectives: Three-dimensional (3D) cell culture technologies allow us to overcome the constraints of two-dimensional methods in different fields like biochemistry and cell biology and in pharmaceutical in vitro tests. In this study, a novel 3D hydrogel sponge scaffold, composed of a crosslinked polyacrylic acid forming a porous matrix, has been developed and characterized. Methods: The scaffold was obtained via an innovative procedure involving thermal treatment followed by a salt-leaching step on a matrix-containing polymer along with a gas-forming agent. Based on experimental design for mixtures, a series of formulations were prepared to study the effect of the three components (polyacrylic acid, NaHCO3 and NaCl) on the scaffold mechanical properties, density, swelling behavior and morphological changes. Physical appearance, surface morphology, porosity, molecular diffusion, transparency, biocompatibility and cytocompatibility were also evaluated. Results: The hydrogel scaffolds obtained show high porosity and good optical transparency and mechanical resistance. The scaffolds were successfully employed to culture several cell lines for more than 20 days. Conclusions: The developed scaffolds could be an important tool, as such or with a specific coating, to obtain a more predictive cellular response to evaluate drugs in preclinical studies or for testing chemical compounds, biocides and cosmetics, thus reducing animal testing.

Development and Characterization of a Three-Dimensional Organotypic In Vitro Oral Cancer Model with Four Co-Cultured Cell Types, Including Patient-Derived Cancer-Associated Fibroblasts.

Background/Objectives: Cancer organoids have emerged as a valuable tool of three-dimensional (3D) cell cultures to investigate tumor heterogeneity and predict tumor behavior and treatment response. We developed a 3D organotypic culture model of oral squamous cell carcinoma (OSCC) to recapitulate the tumor-stromal interface by co-culturing four cell types, including patient-derived cancer-associated fibroblasts (PD-CAFs). Methods: A stainless-steel ring was used twice to create the horizontal positioning of the cancer stroma (adjoining normal oral mucosa connective tissue) and the OSCC layer (surrounding normal oral mucosa epithelial layer). Combined with a structured bi-layered model of the epithelial component and the underlying stroma, this protocol enabled us to construct four distinct portions mimicking the oral cancer tissue arising in the oral mucosa. Results: In this model, α-smooth muscle actin-positive PD-CAFs were localized in close proximity to the OSCC layer, suggesting a crosstalk between them. Furthermore, a linear laminin-γ2 expression was lacking at the interface between the OSCC layer and the underlying stromal layer, indicating the loss of the basement membrane-like structure. Conclusions: Since the specific 3D architecture and polarity mimicking oral cancer in vivo provides a more accurate milieu of the tumor microenvironment (TME), it could be crucial in elucidating oral cancer TME.

Inhibition of OXPHOS induces metabolic rewiring and reduces hypoxia in murine tumor models

IntroductionTumor hypoxia is a feature of many solid malignancies and is known to cause radio resistance. In recent years it has become clear that hypoxic tumor regions also foster an immunosuppressive phenotype and are involved in immunotherapy resistance. It has been proposed that reducing the tumors’ oxygen consumption will result in an increased oxygen concentration in the tissue and improve radio- and immunotherapy efficacy. The aim of this study is to investigate the metabolic rewiring of cancer cells by pharmacological attenuation of oxidative phosphorylation (OXPHOS) and subsequently reduce tumor hypoxia. Material and methodsThe metabolic effects of three OXPHOS inhibitors IACS-010759, atovaquone and metformin were explored by measuring oxygen consumption rate, extra cellular acidification rate, and [18F]FDG uptake in 2D and 3D cell culture. Tumor cell growth in 2D cell culture and hypoxia in 3D cell culture were analyzed by live cell imaging. Tumor hypoxia and [18F]FDG uptake in vivo following treatment with IACS-010759 was determined by immunohistochemistry and ex vivo biodistribution respectively. ResultsIn vitro experiments show that tumor cell metabolism is heterogeneous between different models. Upon OXPHOS inhibition, metabolism shifts from oxygen consumption through OXPHOS towards glycolysis, indicated by increased acidification and glucose uptake. Inhibition of OXPHOS by IACS-010759 treatment reduced diffusion limited tumor hypoxia in both 3D cell culture and in vivo. Although immune cell presence was lower in hypoxic areas compared with normoxic areas, it is not altered following short term OXPHOS inhibition. DiscussionThese results show that inhibition of OXPHOS causes a metabolic shift from OXPHOS towards increased glycolysis in 2D and 3D cell culture. Moreover, inhibition of OXPHOS reduces diffusion limited hypoxia in 3D cell culture and murine tumor models. Reduced hypoxia by OXPHOS inhibition might enhance therapy efficacy in future studies. However, caution is warranted as systemic metabolic rewiring can cause adverse effects.

Non-destructive viability assessment of cancer cell spheroids using dynamic optical coherence tomography with trypan blue validation

3D cell cultures are widely used in biomedical research for the recapitulation of in vivo microenvironments. Viability assessment and monitoring of these intricate conformations remain an open problem as standard cell viability protocols based on colorimetry or microscopy are not directly applicable to intact 3D samples. Optical coherence tomography (OCT) has been explored extensively for subsurface structural and quasi-functional analysis of 3D cell cultures and tissue. Recent studies of dynamic OCT as a source of cellular contrast have found qualitative associations with necrosis in cell spheroids, suggesting potential as a viability marker. We present empirical and validated evidence for dynamic OCT as a quantitative indicator of cell viability in 3D cultures. We analysed over 240 MCF-7 cancer cell spheroids with dynamic OCT and corresponding viability measurements using the trypan blue exclusion assay. Significant effects of common reagents dimethyl sulfoxide (DMSO) and phosphate-buffered saline (PBS) on OCT readouts were noted. We proposed a regression-based OCT brightness normalisation technique that removed reagent-induced OCT intensity biases and helped improve correspondence to the viability assay. These results offer a quantitative biological foundation for further advances of dynamic OCT as a novel non-invasive modality for 3D culture monitoring.

Effects of BYL-719 (alpelisib) on human breast cancer stem cells to overcome drug resistance in human breast cancer.

Breast cancer continues to be a major health concern and is currently the most commonly diagnosed cancer worldwide. Relapse, metastasis, and therapy resistance are major clinical issues that doctors need to address. We believe BYL-719, which is PI3 kinase p110а inhibitor, could also inhibit the breast cancer stem cell phenotype and epithelial-to-mesenchymal transition (EMT). In addition to the PI3K/AKT signaling pathway, BYL-719 can also inhibit essential cancer-related signaling pathways, all of which would ultimately act on the microenvironment of cancer stem cells, which is quite complicated and regulates the characteristics of tumors. These include the stemness and resistance of malignant tumors, plasticity of cancer stem cells, and anti-apoptotic features. A three-dimensional (3D) mammosphere culture method was used in vitro to culture and collect breast cancer stem cells (BCSCs). MTT, clonogenic, and cell apoptosis assays were used to detect cell viability, self-renewal, and differentiation abilities. A sphere formation assay under 3D conditions was used to detect the mammophore inhibition rate of BYL-719. The subpopulation of CD44+CD24- was detected using flow cytometry analysis while EMT biomarkers and essential signaling pathways were detected using western blotting. All the data were analyzed using GraphPad Prism 9 software. BCSC-like cells were obtained by using the 3D cell culture method in vitro. We confirmed that BYL-719 could inhibit BCSC-like cell proliferation in 3D cultures and that the stemness characteristics of BCSC-like cells were inhibited. The PI3K/AKT/mTOR signaling pathway could be inhibited by BYL-719, and the Notch, JAK-STAT and MAPK/ERK signaling pathways which have crosstalk in the tumor microenvironment (TME) are also inhibited. By comparing eribulin-resistant breast cancer cell lines, we confirmed that BYL-719 could effectively overcome drug resistance. The 3D cell culture is a novel and highly effective method for enriching BCSCs in vitro. Furthermore, the stemness and EMT of BCSCs were inhibited by BYL-719 by acting on various signaling pathways. Finally, we believe that drug resistance can be overcome by targeting the BCSCs. Conjugation of BYL-719 with other anti-neoplastic agents may be a promising treatment for this in clinic.

3D Scaffold-Based Culture System Enhances Preclinical Evaluation of Natural Killer Cell Therapy in A549 Lung Cancer Cells.

Cell-based immunotherapies have emerged as promising cancer treatment modalities, demonstrating remarkable clinical efficacy. As interest in applying immune cell-based therapies to solid tumors has gained momentum, experimental models that enable long-term monitoring and mimic clinical administration are increasingly necessary. This study explores the potential of scaffold-based cell culture technologies, specifically three-dimensional (3D) extracellular matrix (ECM)-like frameworks, as promising solutions. These frameworks facilitate unhindered immune cell growth and enable continuous cancer cell culture. The three-dimensional (3D) cell culture model was developed using tailored scaffolds for natural killer (NK) cell culture. Within this framework, A549 lung cancer cells were cocultured with NK cells, allowing real-time monitoring for up to 28 days. The expression of critical markers associated with anticancer drug resistance and epithelial-mesenchymal transition (EMT) was evaluated in cancer cells within this 3D culture context. Compared to conventional 2D monolayer cultures, this 3D scaffold-based culture revealed that solid tumor cells, specifically A549 cells, exhibited heightened resistance to anticancer drugs. Additionally, the 3D culture environment upregulated the expression of EMT markers namely vimentin, N-cadherin, and fibronectin, while NK and zEGFR-CAR-NK cells displayed anticancer effects. In the two-dimensional (2D) coculture, only zEGFR-CAR-NK cells exhibited such effects in the 3D coculture system, highlighting an intriguing inconsistency with the 2D culture model, further confirmed by in vivo experiments. This in vitro 3D cell culture model reliably predicts outcomes in NK immunotherapy experiments. Thus, it represents a valuable tool for investigating drug resistance mechanisms and assessing the efficacy of immune cell-based therapies. By bridging the gap between in vitro and in vivo investigations, this model effectively translates potential treatments into animal models and facilitates rigorous preclinical evaluations.

Highly Bioadaptive Scaffolds with Tuned Porous Structure Templated by Xylan Nanocrystal High Internal Phase Pickering Emulsions.

Fabrication of traditional 3D cell culturing scaffolds requires synthetic polymers or additives, posing a risk of poor biocompatibility and low biodegradability. Pickering emulsions stabilized by biobased nanomaterials can be used as templates to produce scaffolds with facile tunable porous structure, excellent cytocompatibility, and biodegradability. In this study, very stable high internal phase Pickering emulsions (HIPPE) with an oil content of 80% were successfully prepared by xylan hydrate nanocrystals (XNC). The HIPPE can exist stably for more than 30 days, exhibiting a high viscosity. By adding cellulose nanofibers (CNF) and removing the oil phase, scaffolds with a tuned porous structure and enhanced cell culturing ability were successfully fabricated. In the HIPPE templated scaffolds with XNC/CNF, XNC plays a major role in stabilizing the emulsions, while CNF improves the mechanical properties of the scaffolds, both of which are vital to the successful fabrication of the scaffolds. Compared with non-HIPPE templated scaffolds, the HIPPE templated scaffold had a higher porosity and a higher median pore size. The HIPPE templated scaffold was able to maintain 80% cell activity and showed an excellent cytocompatibility. The HIPPE templated scaffolds consisting of XNC and CNF demonstrate great potential in 3D cell culturing for medical purpose.

The crosstalk between primary MSCs and cancer cells in 2D and 3D cultures: potential therapeutic strategies and impact on drug resistance.

The tumor microenvironment (TME) significantly influences cancer progression, and mesenchymal stem cells (MSCs) play a crucial role in interacting with tumor cells via paracrine signaling, affecting behaviors such as proliferation, migration, and epithelial-mesenchymal transition. While conventional 2D culture models have provided valuable insights, they cannot fully replicate the complexity and diversity of the TME. Therefore, developing 3D culture systems that better mimic in vivo conditions is essential. This review delves into the heterogeneous nature of the TME, spotlighting MSC-tumor cellular signaling and advancements in 3D culture technologies. Utilizing MSCs in cancer therapy presents opportunities to enhance treatment effectiveness and overcome resistance mechanisms. Understanding MSC interactions within the TME and leveraging 3D culture models can advance novel cancer therapies and improve clinical outcomes. Additionally, this review underscores the therapeutic potential of engineered MSCs, emphasizing their role in targeted anti-cancer treatments.

Efficacy of photodynamic therapy using 5-aminolevulinic acid-induced photosensitization is enhanced in pancreatic cancer cells with acquired drug resistance

The use of 5-aminolevulinic acid (ALA) as a precursor for protoporphyrin IX (PpIX) is an established photosensitization strategy for photodynamic therapy (PDT) and fluorescence guided surgery. Ongoing studies are focused on identifying approaches to enhance PpIX accumulation as well as to identify tumor sub-types associated with high PpIX accumulation. In this study, we investigated PpIX accumulation and PDT treatment response with respect to nodule size in 3D cultures of pancreatic cancer cells (Panc1) and a derivative subline (Panc1OR), which has acquired drug resistance and exhibits increased epithelial mesenchymal transition. In monolayer and 3D culture dose response studies the Panc1OR cells exhibit significantly higher cell killing at lower light doses than the drug naïve cells. Panc1OR also exhibits increased PpIX accumulation. Further analysis of cell killing efficiency per molecule of intracellular PpIX indicates that the drug resistant cells are intrinsically more responsive to PDT. Additional investigation using exogenous delivery of PpIX also shows higher cell killing in drug resistant cells, under conditions which achieve approximately the same intracellular PpIX. Overall these results are significant as they demonstrate that this example of drug-resistant cells associated with aggressive disease progression and poor clinical outcomes, show increased sensitivity to ALA-PDT.

Biological Scaffolds in 3D Cell Models: Driving Innovation in Drug Discovery.

The discipline of 3D cell modeling is currently undergoing a surge of captivating developments that are enhancing the realism and utility of tissue simulations. Using bioinks which represent cells, scaffolds, and growth factors scientists can construct intricate tissue architectures layer by layer using innovations like 3D bioprinting. Drug testing can be accelerated and organ functions more precisely replicated owing to the precise control that microfluidic technologies and organ-on-chip devices offer over the cellular environment. Tissue engineering is becoming more dynamic with materials that can modify their surroundings with the advent of hydrogels and smart biomaterials. Advances in spheroids and organoids are not only bringing us towards more effective and customized therapies, but they are also improving their ability to resemble actual human tissues. Confocal and two-photon microscopy are examples of advanced imaging methods that provide precise images of the functioning and interaction of cells. Artificial Intelligence models have applications for enhanced scaffold designs and for predicting the response of tissues to medications. Furthermore, via strengthening predictive models, optimizing data analysis, and simplifying 3D cell culture design, artificial intelligence is revolutionizing this field. When combined, these technologies are improving our ability to conduct research and moving us toward more individualized and effective medical interventions.

Auranofin loaded silk fibroin nanoparticles for colorectal cancer treatment.

Colorectal cancer (CRC) is the second most common cause of cancer related deaths worldwide and the prevalence in young people especially is increasing annually. In the search for innovative approaches to treat the disease, drug delivery systems (DDS) are promising owing to their unique properties, which allow improved therapeutic results with lower drug concentrations, overcoming drug resistance and at the same time potentially reducing side effects. Silk fibroin is a biopolymer that can be processed to obtain biocompatible and biodegradable nanoparticles that can be efficiently loaded by surface adsorption with small-molecule therapeutics and allow their transport and sustained release by modulating their pharmacokinetics. Auranofin (AF) has recently been repurposed for its strong anticancer activity and is currently in clinical trials. Its mechanism of action is through the inhibition of thioredoxin reductase enzymes, which play an essential role in several intracellular processes and are overexpressed in some tumours. Taking into account that AF has a low solubility in water, we propose silk fibroin nanoparticles (SFN) as AF carrier in order to improve its bioavailability, increasing cellular absorption and preventing its degradation or avoiding some resistance mechanisms. Here we report the preparation and characterization of a new formulation of AF-loaded silk fibroin nanoparticles (SFN-AF), its functionalization with FITC for the analysis of cellular uptake, as well as its cytotoxic activity against cell lines of human colorectal cancer (HT29 and HCT116) in both 2D and 3D cell cultures. 3D spheroid models provide a 3D environment which mimics the 3D aspects of CRC observed in vivo and represents an effective 3D environment to screen therapeutics for the treatment of CRC. The loaded nanoparticles showed a spherical morphology with a hydrodynamic diameter of ~ 160nm and good stability in aqueous solution due to their negative surface charges. FESEM-EDX analysis revealed a homogeneous distribution of Au clusters with high electron density on the surface of the nanoparticles. SFN-AF incubated in phosphate buffer at 37°C released 77% of the loaded AF over 10 days, showing an initial burst and then sustained release. Flow cytometry analysis showed that FITC-SFN-AF was efficiently internalized by both cell lines, which was confirmed by confocal microscopy imaging. SFN enhanced the cytotoxicity of AF in 2D cultures in both CRC lines. Promising results were also obtained in 3D culture paving the way for future application of this strategy as a therapy for CRC.

TGF-β effects on adipogenesis of 3T3-L1 cells differ in 2D and 3D cell culture conditions.

The TGF-β superfamily plays a pivotal role in the regulation of adipogenesis, but little is known about the potential differential role of the three isoforms of TGF-β, TGF-β-1~3. To further elucidate their role, two-dimensionally (2D) and three-dimensionally (3D) cultured 3T3-L1 mouse preadipocytes were subjected to the following analyses: (a) qPCR analysis of adipogenesis-related factors and major extracellular matrix protein (2D and /or 3D), (b) lipid staining by Oil Red O (2D) or BODIPY (3D), (c) Seahorse cellular metabolic measurement (2D), and (d) size and stiffness measurements of 3D 3T3-L1 spheroids. In the 2D cultured 3T3-L1 cells, mRNA expression levels of adipogenesis-related genes and Oil Red O lipid staining intensity were significantly increased by adipogenesis and they were substantially decreased following treatment with 0.1 nm TGF-β isoforms, with TGF-β2 having the greater effects. Consistent with these results, treatment with TGF-β2 resulted in suppression of mitochondrial and glycolytic functions in 2D cultured 3T3-L1 cells. However, the inhibitory effect of TGF-β on adipogenesis decreased under 3D spheroid culture conditions and TGF-β isoforms did not affect adipogenesis-induced (a) enlargement and downsizing of 3T3-L1 spheroids, (b) increase in BODIPY lipid staining intensity, and (c) up-regulation of the mRNA expression of adipogenesis-related genes. The findings presented herein suggest that the three TGF-β isoforms have different suppressive effects on adipogenesis-related cellular properties of 2D cultured 3T3-L1 cells and that their effects decrease under 3D spheroid culture conditions.

8468 Development And Characterisation Of Three-Dimensional Cell Culture Models Of Adrenocortical Carcinoma

Abstract Disclosure: S. Feely: None. N. Mullen: None. P. Donlon: None. C. Hantel: None. M.C. dennedy: None. Adrenocortical carcinoma (ACC) is a rare malignancy carrying a poor prognosis and limited treatment options. Surgical resection is the only option for cure; but unsuitable for advanced disease. Mitotane is the approved medical therapy, but associated with treatment resistance and adverse effects. Newer therapies, such as immune checkpoint inhibitors, have limited success. Development of improved therapies is limited by current pre-clinical disease models. No available model reflects the tumour micro-environment. Three-dimensional (3D) cell culture models are increasingly used in cancer research (6), with a paucity of developed models in ACC. In the current study, we developed novel 3D models of ACC using a type-1 collagen matrix. We then characterised these as representative ACC disease models . 3D cell culture models of ACC were optimised by embedding ACC cell lines, MUC-1, HAC15 and H295R within a type-1 Collagen matrix at differing cell numbers. Expression of type-1 collagen in ACC primary tumours was determined using immunohistochemistry (n=4). Cell viability for each model was assessed by evaluating sytox blue staining by Flow Cytometry. Metabolic activity of ACC cells within the matrix was determined using AlamarBlue staining. Prolferative activity was assessed using Ki67. Steroidogenesis was evaluated by measuring cortisol, aldosterone and androstenedione using LC-MS/MS.. Expression of CYP11B1, CYP11B2 CYP17, and StAR was measured using RT-qPCR. Type 1 collagen is strongly expressed in ACC tumour microenvironment. MUC-1, H295R and HAC15 cells were successfully cultured in a type 1 collagen matrix. MUC-1 cells cultured in the collagen matrix remain viable throughout the period of experimentation with optimum viability between 14 and 21 days. H295R cells also remain viable with optimum viability at an earlier stage of 7-14 days. HAC15 cells demonstrate high resilience in 3D cell culture with maximum viability throughout the entire period of experimentation up to 21 days. All three models increase their metabolic and proliferative activity over time. All three steroids are expressed by all three models with an increase in aldosterone secretion observed in 3D HAC15 and H295R models compared to monolayer (p>0.001) at days 7 and 14. All models express key steroidogenic enzymes. 3D ACC cell culture models were developed successfully using collagen type 1 abundant in ACC. Typical characteristics of the ACC tumour environment included (i) the presence of live and necrotic cells (ii) high metabolic activity and proliferation, reflective of cell turnover.. Capacity of cells to spread and proliferate within the 3D cell culture models was limited by available collagen substrate. Steroidogenic capacity was demonstrated in 3D cell culture. This model therefore retained key characteristics of ACC and shows promise as an animal-sparing, pre-clinical model. Presentation: 6/1/2024

3D-Printable Gelatin Methacrylate-Xanthan Gum Hydrogel Bioink Enabling Human Induced Pluripotent Stem Cell Differentiation into Cardiomyocytes.

We describe the development of a bioink to bioprint human induced pluripotent stem cells (hiPSCs) for possible cardiac tissue engineering using a gelatin methacrylate (GelMA)-based hydrogel. While previous studies have shown that GelMA at a low concentration (5% w/v) allows for the growth of diverse cells, its 3D printability has been found to be limited by its low viscosity. To overcome that drawback, making the hydrogel both compatible with hiPSCs and 3D-printable, we developed an extrudable GelMA-based bioink by adding xanthan gum (XG). The GelMA-XG composite hydrogel had an elastic modulus (~9 kPa) comparable to that of cardiac tissue, and enabled 3D printing with high values of printing accuracy (83%) and printability (0.98). Tests with hiPSCs showed the hydrogel's ability to promote their proliferation within both 2D and 3D cell cultures. The tests also showed that hiPSCs inside hemispheres of the hydrogel were able to differentiate into cardiomyocytes, capable of spontaneous contractions (average frequency of ~0.5 Hz and amplitude of ~2%). Furthermore, bioprinting tests proved the possibility of fabricating 3D constructs of the hiPSC-laden hydrogel, with well-defined line widths (~800 μm).

Barrier-free, open-top microfluidic chip for generating two distinct, interconnected 3D microvascular networks

Developing microphysiological cell culture platforms with a three-dimensional (3D) microenvironment has been a significant advancement from traditional monolayer cultures. Still, most of the current microphysiological platforms are limited in closed designs, i.e. are not accessible after 3D cell culture loading. Here, we report an open-top microfluidic chip which enables the generation of two sequentially loaded 3D cell cultures without physical barriers restricting the nurture, gas exchange and cellular communication. As a proof-of-concept, we demonstrated the formation of two 3D vasculatures, one in the upper and the other in the lower compartment, under three distinct flow conditions: asymmetric side-to-center, symmetric side-to-center and symmetric center-to-side. We used computational modelling to characterize initial flow pressures in cell culture compartments. We showed prominent vessel formation and branched vasculatures in upper and lower cell culture compartments with interconnecting, lumenized vessels with in vivo-relevant diameter in all flow conditions. With advanced image processing, we quantified and compared the overall vascular network volume and the total length formed in asymmetric side-to-center, symmetric side-to-center and symmetric center-to-side flow conditions. Our results indicate that the developed chip can house two distinct 3D cell cultures with merging vessels between compartments and by providing asymmetric side-to-center or symmetric center-to-side flow vascular morphogenesis is enhanced in terms of overall network length. The developed open-top microfluidic chip may find various applications in generation of tissue-specific 3D-3D co-cultures for studying cellular interactions in vascularized tissues and organs.

Enhanced Osteogenesis in 2D and 3D Culture Systems Using RGD Peptide and α-TCP Phase Transition within Alginate-Based Hydrogel.

Cell-laden hydrogels have been extensively investigated in various tissue engineering fields bytheir potential capacity to deposit numerous types of cells in a specific area. They are largely used in soft-tissue engineering applications because of their low mechanical strength. In addition, sodium alginate is well-known for its encapsulation, loading capacity and for being easily controllable; however, it lacks cell-binding ligands and hence the ability to adhere cells. In this study, it is aimed to enhance osteogenesis in cells encapsulated in alginate and improve its mechanical properties by introducing a synthetic peptide and calcium phosphate phase transition. To increase cell-hydrogel interactions and increasing cell viability, an RGD peptide is added to a photocrosslinkable methacrylate-modified alginate, and alpha-tricalcium phosphate (α-TCP) is added to the hydrogel to increase its mechanical strength via phase transition. Cell proliferation, growth, and differentiation are assessed in both 2D and 3D cell cultures. The addition of α-TCP significantly improved the mechanical properties of the hydrogel. Moreover, the RGD peptide and α-TCP showed a synergistic effect with significantly improved cell adhesion and osteogenesis in both 2D and 3D cell cultures. Therefore, the functional hydrogel developed in this study can potentially be used for bone tissue regeneration.

Metallic-based phthalocyanine nanoemulsions for photodynamic purging of ovarian tissue in leukemia patients

For cancer patients with a high risk of ovarian tissue metastasis, ovarian autotransplantation is not advised due to the potential spread of malignant cells. Ex vivo purging of ovarian fragments may offer a more suitable alternative for fertility restoration. Eradicating malignant cells should be done selectively without affecting follicles or ovarian stromal cells (SCs). As a clinically licensed method, photodynamic therapy (PDT) is a minimally invasive treatment to destroy cancer cells. This study evaluates the effectiveness of nanoemulsions (NE) containing two phthalocyanine photosensitizers; aluminum (III) phthalocyanine (AlPc) and zinc (II) phthalocyanine (ZnPc) in eliminating cancer cells. Human leukemic malignant (HL-60) and ovarian stromal cells (SCs) were treated with AlPc/ZnPc loaded NEs with or without diode laser irradiation. HL-60 leukemia cells in 2D culture were eliminated by treatment with 10nM AlPc-NE or 0.1µM ZnPc-NE, while no toxicity was observed in SCs. In 3D culture models, although the cells showed more resistance to the NEs as a result of limited oxygen and photosensitizer penetration, the treatment remained selective for cancer cells. These approaches have the potential to eliminate malignant cells from ovarian tissue fragments.

Construction of a lung cancer 3D culture model based on alginate/gelatin micro-beads for drug evaluation.

Lung cancer is one of the most common malignant tumors worldwide. Despite advances in lung cancer treatment, patients still face challenges related to drug resistance and recurrence. Current methods for evaluating anti-cancer drug activity are insufficient, as they rely on two-dimensional (2D) cell culture and animal models. Therefore, the development of an in vitro drug evaluation model capable of predicting individual sensitivity to anti-cancer drugs would greatly enhance the success rate of drug treatments for lung cancer patients. The purpose of this research is to utilise conditional reprogramming technology to cultivate patient-derived lung cancer cells and to construct an in vitro 3D culture model using sodium alginate (SA) and gelatin. The aim is to study the biological characteristics of cells in the 3D culture model and to further investigate the sensitivity of anti-cancer drugs based on the alginate-gelatin 3D culture model. This approach provides new means and insights for personalized precision anti-cancer therapy and the development of new anti-cancer drugs. Conditional reprogramming technology was used to generate conditionally reprogrammed lung adenocarcinoma cells (CRLCs). Alginate-gelatin hydrogel micro-beads were created to explore their potential use in the assessment of anti-cancer drugs. Cell proliferation was also examined using the MTS assay method. Live/dead staining was performed to estimate cell distribution and viability using calcein acetoxymethyl ester/propidium iodide (calcein-AM/PI) double staining. Protein expression was assessed by Western blot. The cells grown in the three-dimensional (3D) culture were in a state of continuous proliferation, and there was an obvious phenomenon of cell mass growth. The drug sensitivity assay results demonstrated that compared with the 2D-grown cells, the CRLCs grown in the alginate-gelatin hydrogel micro-beads exhibited more resistance to anti-cancer drugs. The results also showed that the 3D-cultured CRLCs showed greater protein expression levels of stem cell hallmarks, such as Nanog Homeobox (NANOG), SRY-Box Transcription Factor 2 (SOX-2), and aldehyde dehydrogenase 1 family member A1 (ALDH1A1), than the 2D-grown cells. These findings suggest that the 3D hydrogel cell culture models more closely mimicked the in vivo biological and clinical behavior of cells, and demonstrated higher innate resistance to anti-cancer drugs than the 2D cell culture models, and thus could serve as valuable tools for diagnosis, drug screening, and personalized medicine.

Protein absorption alters the cellular targeting of glycopolymeric nanoparticles

Glycopolymeric nanoparticles are widely employed in biomedical applications due to their high targeting ability, biocompatibility, and biodegradability. The pendant saccharides serve as targeting ligands to be explicitly coordinated to receptors on cell membrane surfaces. However, proteins in the blood often absorb onto the nanoparticle surface, potentially impacting the exposure and effectiveness of the saccharide ligands for targeted delivery. To elucidate the protein absorption effects, we prepared micelles decorated with different percentages of fructose moieties and evaluated the bioactivity of nanoparticles using 2D cell culture, tumor spheroid, liver organoid, and coculture models. The 2D cell culture model did not show a significant difference in activity between protein-coated and non-coated micelles. However, a dramatic decrease in cellular uptake and penetration ability of micelles was observed in 3D tumor spheroids after protein absorption. Additionally, protein absorption notably increased micelle uptake in liver organoids. In the coculture model, protein absorption reduced micelle uptake in tumor spheroids while favoring uptake in liver organoids. Our work suggests that decreasing non-specific protein absorption of glycopolymeric nanoparticles could enhance their delivery efficiency. These findings underscore the importance of understanding protein interactions in nanoparticle applications for drug delivery.

Impact of perfusion on neuronal development in human derived neuronal networks.

Advanced in vitro models of the brain have evolved in recent years from traditional two-dimensional (2D) ones, based on rodent derived cells, to three-dimensional (3D) ones, based on human neurons derived from induced pluripotent stem cells. To address the dynamic changes of the tissue microenvironment, bioreactors are used to control the in vitro microenvironment for viability, repeatability, and standardization. However, in neuronal tissue engineering, bioreactors have primarily been used for cell expansion purposes, while microfluidic systems have mainly been employed for culturing organoids. In this study, we explored the use of a commercial perfusion bioreactor to control the culture microenvironment of neuronal cells in both 2D and 3D cultures. Namely, neurons differentiated from human induced pluripotent stem cells (iNeurons) were cultured in 2D under different constant flow rates for 72 h. The impact of different flow rates on early-stage neuronal development and synaptogenesis was assessed by morphometric characterization and synaptic analysis. Based on these results, two involving variable flow rates were developed and applied again in 2D culture. The most effective protocol, in terms of positive impact on neuronal development, was then used for a preliminary study on the application of dynamic culturing conditions to neuronal cells in 3D. To this purpose, both iNeurons, co-cultured with astrocytes, and the human neuroblastoma cells SH-SY5Y were embedded into a hydrogel and maintained under perfusion for up to 28 days. A qualitative evaluation by immunocytochemistry and confocal microscopy was carried out to assess cell morphology and the formation of a 3D neuronal network.