ECM Mechano-Sensing Regulates Cytoskeleton Assembly and Receptor-Mediated Endocytosis of Nanoparticles

Regulation of Cell-Nanoparticle Interactions through Mechanobiology

Bio-nano interactions have been extensively explored in nanomedicine to develop selective delivery strategies and reduce systemic toxicity. To enhance the delivery of nanocarriers to cancer cells and improve the therapeutic efficiency, different nanomaterials have been developed. However, the limited clinical translation of nanoparticle-based therapies, largely due to issues associated with poor targeting, requires a deeper understanding of the biological phenomena underlying cell-nanoparticle interactions. In this context, we investigate the molecular and cellular mechanobiology parameters that control such interactions. We demonstrate that the pharmacological inhibition or the genetic ablation of the key mechanosensitive component of the Hippo pathway, i.e., yes-associated protein, enhances nanoparticle internalization by 1.5-fold. Importantly, this phenomenon occurs independently of nanoparticle properties, such as size, or cell properties such as surface area and stiffness. Our study reveals that the internalization of nanoparticles in target cells can be controlled by modulating cell mechanosensing pathways, potentially enhancing nanotherapy specificity.

HiViPore: a highly viable in-flow compression for a one-step cell mechanoporation in microfluidics to induce a free delivery of nano- macro-cargoes

BACKGROUND

Among mechanoporation techniques for intracellular delivery, microfluidic approaches succeed in high delivery efficiency and throughput. However, especially the entry of large cargoes (e.g. DNA origami, mRNAs, organic/inorganic nanoparticles) is currently impaired since it requires large cell membrane pores with the need to apply multi-step processes and high forces, dramatically reducing cell viability.

RESULTS

Here, HiViPore presents as a microfluidic viscoelastic contactless compression for one-step cell mechanoporation to produce large pores while preserving high cell viability. Inducing an increase of curvature at the equatorial region of cells, formation of a pore with a size of ~ 1 μm is obtained. The poration is coupled to an increase of membrane tension, measured as a raised fluorescence lifetime of 12% of a planarizable push-pull fluorescent probe (Flipper-TR) labelling the cell plasma membrane. Importantly, the local disruptions of cell membrane are transient and non-invasive, with a complete recovery of cell integrity and functions in ~ 10 min. As result, HiViPore guarantees cell viability as high as ~ 90%. In such conditions, an endocytic-free diffusion of large nanoparticles is obtained with typical size up to 500 nm and with a delivery efficiency up to 12 times higher than not-treated cells.

CONCLUSIONS

The proposed one-step contactless mechanoporation results in an efficient and safe approach for advancing intracellular delivery strategies. In detail, HiViPore solves the issues of low cell viability when multiple steps of poration are required to obtain large pores across the cell plasma membrane. Moreover, the compression uses a versatile, low-cost, biocompatible viscoelastic fluid, thus also optimizing the operational costs. With HiViPore, we aim to propose an easy-to-use microfluidic device to a wide range of users, involved in biomedical research, imaging techniques and nanotechnology for intracellular delivery applications in cell engineering.

Impact of mechanical cues on key cell functions and cell-nanoparticle interactions

In recent years, it has been recognized that mechanical forces play an important regulative role in living organisms and possess a direct impact on crucial cell functions, ranging from cell growth to maintenance of tissue homeostasis. Advancements in mechanobiology have revealed the profound impact of mechanical signals on diverse cellular responses that are cell type specific. Notably, numerous studies have elucidated the pivotal role of different mechanical cues as regulatory factors influencing various cellular processes, including cell spreading, locomotion, differentiation, and proliferation. Given these insights, it is unsurprising that the responses of cells regulated by physical forces are intricately linked to the modulation of nanoparticle uptake kinetics and processing. This complex interplay underscores the significance of understanding the mechanical microenvironment in shaping cellular behaviors and, consequently, influencing how cells interact with and process nanoparticles. Nevertheless, our knowledge on how localized physical forces affect the internalization and processing of nanoparticles by cells remains rather limited. A significant gap exists in the literature concerning a systematic analysis of how mechanical cues might bias the interactions between nanoparticles and cells. Hence, our aim in this review is to provide a comprehensive and critical analysis of the existing knowledge regarding the influence of mechanical cues on the complicated dynamics of cell-nanoparticle interactions. By addressing this gap, we would like to contribute to a detailed understanding of the role that mechanical forces play in shaping the complex interplay between cells and nanoparticles.

Impact of ionizing radiation on cell-ECM mechanical crosstalk in breast cancer

The stiffness of the extracellular matrix plays a crucial role in cell motility and spreading, influencing cell morphology through cytoskeleton organization and transmembrane proteins' expression. In this context, mechanical characterization of both cells and the extracellular matrix gains prominence for enhanced diagnostics and clinical decision-making. Here, we investigate the combined effect of mechanotransduction and ionizing radiations on altering cells' mechanical properties, analysing mammary cell lines (MCF10A and MDA-MB-231) after X-ray radiotherapy (2 and 10 Gy). We found that ionizing radiations sensitively affect adenocarcinoma cells cultured on substrates mimicking cancerous tissue stiffness (15 kPa), inducing an increased structuration of paxillin-rich focal adhesions and cytoskeleton: this process translates in the augmentation of tension at the actin filaments level, causing cellular stiffness and consequently affecting cytoplasmatic/nuclear morphologies. Deeper exploration of the intricate interplay between mechanical factors and radiation should provide novel strategies to orient clinical outcomes.

Mechanism of RGD-conjugated nanodevice binding to its target protein integrin αVβ3 by atomistic molecular dynamics and machine learning

Active targeting strategies have been proposed to enhance the selective uptake of nanoparticles (NPs) by diseased cells, and recent experimental findings have proven the effectiveness of this approach. However, no mechanistic studies have yet revealed the atomistic details of the interactions between ligand-activated NPs and integrins. As a case study, here we investigate, by means of advanced molecular dynamics simulations (MD) and machine learning methods (namely equilibrium MD, binding free energy calculations and training of self-organized maps), the interaction of a cyclic-RGD-conjugated PEGylated TiO2 NP (the nanodevice) with the extracellular segment of integrin αVβ3 (the target), the latter experimentally well-known to be over-expressed in several solid tumors. Firstly, we proved that the cyclic-RGD ligand binding to the integrin pocket is established and kept stable even in the presence of the cumbersome realistic model of the nanodevice. In this respect, the unsupervised machine learning analysis allowed a detailed comparison of the ligand/integrin binding in the presence and in the absence of the nanodevice, which unveiled differences in the chemical features. Then, we discovered that unbound cyclic RGDs conjugated to the NP largely contribute to the interactions between the nanodevice and the integrin. Finally, by increasing the density of cyclic RGDs on the PEGylated TiO2 NP, we observed a proportional enhancement of the nanodevice/target binding. All these findings can be exploited to achieve an improved targeting selectivity and cellular uptake, and thus a more successful clinical outcome.

Role of the mechanical microenvironment on CD-44 expression of breast adenocarcinoma in response to radiotherapy

The biological effects of ionizing radiation are exploited in the clinical practice of radiotherapy to destroy tumour cells while sparing the surrounding normal tissue. While most of the radiotherapy research focused on DNA damage and repair, recently a great attention is going to cells' interactions with the mechanical microenvironment of both malignant and healthy tissues after exposure. In fact, the stiffness of the extracellular matrix can modify cells' motility and spreading through the modulation of transmembrane proteins and surface receptors' expression, such as CD-44. CD-44 receptor has held much interest also in targeted-therapy due to its affinity with hyaluronic acid, which can be used to functionalize biodegradable nanoparticles loaded with chemotherapy drugs for targeted therapy. We evaluated changes in CD-44 expression in two mammary carcinoma cell lines (MCF10A and MDA-MB-231) after exposure to X-ray (2 or 10 Gy). To explore the role of the mechanical microenvironment, we mimicked tissues' stiffness with polyacrylamide's substrates producing two different elastic modulus values (0.5 and 15 kPa). We measured a dose dependent increase in CD-44 relative expression in tumour cells cultured in a stiffer microenvironment. These findings highlight a crucial connection between the mechanical properties of the cell's surroundings and the post-radiotherapy expression of surface receptors.

YAP Signaling Regulates the Cellular Uptake and Therapeutic Effect of Nanoparticles

Interactions between living cells and nanoparticles are extensively studied to enhance the delivery of therapeutics. Nanoparticles size, shape, stiffness, and surface charge are regarded as the main features able to control the fate of cell-nanoparticle interactions. However, the clinical translation of nanotherapies has so far been limited, and there is a need to better understand the biology of cell-nanoparticle interactions. This study investigates the role of cellular mechanosensitive components in cell-nanoparticle interactions. It is demonstrated that the genetic and pharmacologic inhibition of yes-associated protein (YAP), a key component of cancer cell mechanosensing apparatus and Hippo pathway effector, improves nanoparticle internalization in triple-negative breast cancer cells regardless of nanoparticle properties or substrate characteristics. This process occurs through YAP-dependent regulation of endocytic pathways, cell mechanics, and membrane organization. Hence, the study proposes targeting YAP may sensitize triple-negative breast cancer cells to chemotherapy and increase the selectivity of nanotherapy.

Vibropolyfection: coupling polymer-mediated gene delivery to mechanical stimulation to enhance transfection of adherent cells

BACKGROUND

With the success of recent non-viral gene delivery-based COVID-19 vaccines, nanovectors have gained some public acceptance and come to the forefront of advanced therapies. Unfortunately, the relatively low ability of the vectors to overcome cellular barriers adversely affects their effectiveness. Scientists have thus been striving to develop ever more effective gene delivery vectors, but the results are still far from satisfactory. Therefore, developing novel strategies is probably the only way forward to bring about genuine change. Herein, we devise a brand-new gene delivery strategy to boost dramatically the transfection efficiency of two gold standard nucleic acid (NA)/polymer nanoparticles (polyplexes) in vitro.

RESULTS

We conceived a device to generate milli-to-nanoscale vibrational cues as a function of the frequency set, and deliver vertical uniaxial displacements to adherent cells in culture. A short-lived high-frequency vibrational load (t = 5 min, f = 1,000 Hz) caused abrupt and extensive plasmalemma outgrowths but was safe for cells as neither cell proliferation rate nor viability was affected. Cells took about 1 hr to revert to quasi-naïve morphology through plasma membrane remodeling. In turn, this eventually triggered the mechano-activated clathrin-mediated endocytic pathway and made cells more apt to internalize polyplexes, resulting in transfection efficiencies increased from 10-to-100-fold. Noteworthy, these results were obtained transfecting three cell lines and hard-to-transfect primary cells.

CONCLUSIONS

In this work, we focus on a new technology to enhance the intracellular delivery of NAs and improve the transfection efficiency of non-viral vectors through priming adherent cells with a short vibrational stimulation. This study paves the way for capitalizing on physical cell stimulation(s) to significantly raise the effectiveness of gene delivery vectors in vitro and ex vivo.

In vitro effects of combustion generated carbon dots on cellular parameters in healthy and cancerous breast cells

Carbon nanomaterials are an inventive class of materials with wide applications in state-of-the-art bioimaging and therapeutics. They allow a broad range of tunable and integrated advantages of structural flexibility, chemical and thermal stability, upright electrical conductivity, and the option of scale-up and mass production. In the context of nanomedicine, carbon nanomaterials have been used extensively to mitigate the serious side effects of conventional chemotherapy and also to enable early cancer diagnostics, given their wide range of tunable properties. A class of carbon nanomaterials, called carbon dots (CDs) are small carbon-based nanoparticles and have been a valued discovery due to their photoluminescence, low photobleaching, and high surface area to mass ratio. The process of producing these CDs had so far been a high energy demanding process involving wet chemistry for purification. A one-step tunable production of luminescent CDs from fuel rich combustion reactors was recently presented by our group. In this paper, we explore the effects of these yellow luminescent combustion-generated CDs in MCF7 adenocarcinoma and MCF10a normal breast epithelial cells. We observed that these CDs, also at nontoxic doses, can affect basic cellular functions, such as cell cycle and proliferation; induce substantial changes on the physical parameters of the plasma membrane; and change the overall appearance of a cell in terms of morphology.

A Hyaluronic Acid-Based Formulation with Simultaneous Local Drug Delivery and Antioxidant Ability for Active Viscosupplementation

Hyaluronic acid (HA) and its derivatives are widely used for intra-articular injection to augment compromised viscoelastic properties of damaged synovial fluid. Combining HA-based devices with anti-inflammatory drugs or bioactive principles in order to provide an additional benefit to the viscosupplementation is emerging as a new promising approach to improve the clinical outcome. Here, we aim to design a novel active viscosupplementation agent that can load and release hydrophobic drugs and at the same time possessing antioxidant properties. Optimized ternary systems named HCV based on HA, (2-hydroxypropyl)-β-cyclodextrin (CD), and vitamin E (VE), without being engaged in formal chemical bonding with each other, showed the best viscoelastic and lubrication properties along with antioxidant capabilities, able to solubilize and release DF. The physical-chemical characterization suggested that the HCV system displayed rheological synergism and higher thermal stability because of the presence of VE and its antioxidant activity, and the loading of hydrophobic drugs was improved by the presence of CD and VE. Cell morphology and viability tests on L929 cells exhibited high biocompatibility of the HCV system with higher level expression of anti-inflammatory interleukin-10.

ECM Mechanoregulation in Malignant Pleural Mesothelioma

Malignant pleural mesothelioma is a relatively rare, but devastating tumor, because of the difficulties in providing early diagnosis and effective treatments with conventional chemo- and radiotherapies. Patients usually present pleural effusions that can be used for diagnostic purposes by cytological analysis. This effusion cytology may take weeks or months to establish and has a limited sensitivity (30%-60%). Then, it is becoming increasingly urgent to develop alternative investigative methods to support the diagnosis of mesothelioma at an early stage when this cancer can be treated successfully. To this purpose, mechanobiology provides novel perspectives into the study of tumor onset and progression and new diagnostic tools for the mechanical characterization of tumor tissues. Here, we report a mechanical and biophysical characterization of malignant pleural mesothelioma cells as additional support to the diagnosis of pleural effusions. In particular, we examined a normal mesothelial cell line (Met5A) and two epithelioid mesothelioma cell lines (REN and MPP89), investigating how malignant transformation can influence cellular function like proliferation, cell migration, and cell spreading area with respect to the normal ones. These alterations also correlated with variations in cytoskeletal mechanical properties that, in turn, were measured on substrates mimicking the stiffness of patho-physiological ECM.

Synthesis and Characterization of Folate-Modified Cell Membrane Mimetic Copolymer Micelles for Effective Tumor Cell Internalization

The inefficient targeting and phagocytic clearance of nanodrug delivery systems are two major obstacles in cancer therapy. Here, inspired by the special properties of zwitterionic polymers and folic acid (FA), a partly biodegradable copolymer of FA-modified poly(ε-caprolactone) block poly(2-methacryloxoethyl phosphorylcholine), PCL-b-PMPC-FA, was synthesized via atom transfer radical polymerization (ATRP) and click reaction. Non-FA-modified copolymer PCL-b-PMPC was also synthesized as a control. The hydrodynamic diameter of the PCL-b-PMPC-FA micelles is 158 nm (PDI 0.261), slightly larger than that of the PCL-b-PMPC micelles (139 nm, PDI 0.242). The drug doxorubicin (DOX) could be entrapped in the micelles, and as the pH decreased from 7.4 to 5.0, DOX release (in vitro) was accelerated. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that both the PCL-b-PMPC and the PCL-b-PMPC-FA micelles showed low toxicity to L929, HeLa, and MCF-7 cells. In addition, the DOX-loaded micelles, PCL-b-PMPC/DOX and PCL-b-PMPC-FA/DOX micelles, exhibited low toxicity to L929 cells but high toxicity to HeLa and MCF-7 cells, especially the PCL-b-PMPC-FA/DOX micelles. HeLa and MCF-7 cell uptakes of the PCL-b-PMPC-FA/DOX micelles were 4.8 and 4.5 times higher than that of the PCL-b-PMPC/DOX micelles, respectively. Therefore, PCL-b-PMPC-FA micelles have great potential for developing drug delivery systems with extended circulation times and tumor-targeting properties.

MSN, MWCNT and ZnO nanoparticle-induced CHO-K1 cell polarisation is linked to cytoskeleton ablation

BACKGROUND

The cellular response to nanoparticles (NPs) for the mechanical clue and biochemical changes are unexplored. Here, we provide the comprehensive analysis of the Chinese Hamster Ovary (CHO-K1) cell line to study cell behaviour following the exposure of mesoporous silica nanoparticle (MSN), multiwall carbon nanotubes (MWCNTs), and zinc oxide (ZnO) NPs.

RESULTS

Through the high-throughput proteomic study, we observed that the effect of NPs is alone not restricted to cell viability but also on cell polarisation. In the case of MSN, no drastic changes were observed in cellular morphology, but it upregulated chaperons that might prevent protein aggregation. However, MWCNT showed elongated cell appearance with numerous cytoplasmic vacuoles, and induce lamellipodia formation through actin polymerisation. The cytoskeleton remodelling was accompanied by the increased expression of Dlc-1, cofilin and Rac1 proteins. While ZnO NPs resulted in the rounded cell morphology along with nuclear abnormalities. The proteome analysis revealed that UBXN11 control cell roundness and DOCK3 leads to actin stress fibre formation and finally, loss of cell adhesion. It enhances the expression of catastrophic DNA damage and apoptotic proteins, which was unrecoverable even after 72 h, as confirmed by the colony formation assay. All three NPs trigger over-expression of the endocytic pathway, ubiquitination, and proteasomal complex proteins. The data indicate that ZnO and MSN entered into the cells through clathrin-mediated pathways; whereas, MWCNT invades through ER-mediated phagocytosis.

CONCLUSIONS

Based on the incubation and concentration of NPs, our work provides evidence for the activation of Rac-Rho signalling pathway to alter cytoskeleton dynamics. Our results assist as a sensitive early molecular readout for nanosafety assessment.

Reprogramming normal cells into tumour precursors requires ECM stiffness and oncogene-mediated changes of cell mechanical properties

Defining the interplay between the genetic events and microenvironmental contexts necessary to initiate tumorigenesis in normal cells is a central endeavour in cancer biology. We found that receptor tyrosine kinase (RTK)-Ras oncogenes reprogram normal, freshly explanted primary mouse and human cells into tumour precursors, in a process requiring increased force transmission between oncogene-expressing cells and their surrounding extracellular matrix. Microenvironments approximating the normal softness of healthy tissues, or blunting cellular mechanotransduction, prevent oncogene-mediated cell reprogramming and tumour emergence. However, RTK-Ras oncogenes empower a disproportional cellular response to the mechanical properties of the cell's environment, such that when cells experience even subtle supra-physiological extracellular-matrix rigidity they are converted into tumour-initiating cells. These regulations rely on YAP/TAZ mechanotransduction, and YAP/TAZ target genes account for a large fraction of the transcriptional responses downstream of oncogenic signalling. This work lays the groundwork for exploiting oncogenic mechanosignalling as a vulnerability at the onset of tumorigenesis, including tumour prevention strategies.

Mechanical behavior of bioactive poly(ethylene glycol) diacrylate matrices for biomedical application

The biomedical applications of physically entangled polymeric hydrogels are generally limited due to their weak mechanical properties, rapid swelling and dissolution in physiologically relevant environment. Chemical crosslinking helps stabilizing hydrogel structure and enhancing mechanical properties, thereby allowing a higher stability in phisiological environment. In this context, it is known that the mechanical properties of the hydrogel are affected by both the molecular weight (MW) of the starting polymer and the concentration of the crosslinker. Here, our aim was to assess the influence of polymer MW and concentration in the precursor solution on the mechanical features of the final hydrogel and their influence on cells-material interaction. In detail, 3D synthetic matrices based on poly(ethylene glycol) diacrylate (PEGDA) at two molecular weights (PEG 700 and PEG 3400) and at three different concentrations (10, 20, 40 w/v %), which were photopolymerized using darocour as an initiator, were studied. Then, infrared and swelling analyses, along with a comprehensive mechanical characterization of the obtained hydrogels (i.e. oscillatory shear and confined compression tests), were performed. Finally, to evaluate the influence of the mechanical features on the biological behaviour, the hydrogels were characterized in terms of cell adhesion percentage and cell viability after functionalizing the substrates with RGD peptide at three different concentrations. Results have demonstrated that both the Young's modulus (E) in compression and the elastic modulus (G') in shear of the hydrogels increase with increasing polymer precursor concentration. E decreased as MW increased, and the differences are more relevant for more concentrated hydrogels. On the contrary, G' appears to increase with increasing PEGDA MW and in particular for the lowest polymer precursor concentration. The biological results have demonstrated that cells cultured for longer times seem to prefer PEG 3400 hydrogels with a larger mesh size structure that posses higher viscoelastic properties in shear.

Effect of AFM Nanoindentation Loading Rate on the Characterization of Mechanical Properties of Vascular Endothelial Cell

Vascular endothelial cells form a barrier that blocks the delivery of drugs entering into brain tissue for central nervous system disease treatment. The mechanical responses of vascular endothelial cells play a key role in the progress of drugs passing through the blood-brain barrier. Although nanoindentation experiment by using AFM (Atomic Force Microscopy) has been widely used to investigate the mechanical properties of cells, the particular mechanism that determines the mechanical response of vascular endothelial cells is still poorly understood. In order to overcome this limitation, nanoindentation experiments were performed at different loading rates during the ramp stage to investigate the loading rate effect on the characterization of the mechanical properties of bEnd.3 cells (mouse brain endothelial cell line). Inverse finite element analysis was implemented to determine the mechanical properties of bEnd.3 cells. The loading rate effect appears to be more significant in short-term peak force than that in long-term force. A higher loading rate results in a larger value of elastic modulus of bEnd.3 cells, while some mechanical parameters show ambiguous regulation to the variation of indentation rate. This study provides new insights into the mechanical responses of vascular endothelial cells, which is important for a deeper understanding of the cell mechanobiological mechanism in the blood-brain barrier.

Adhesion and Migration Response to Radiation Therapy of Mammary Epithelial and Adenocarcinoma Cells Interacting with Different Stiffness Substrates

The structural and mechanical properties of the microenvironmental context have a profound impact on cancer cell motility, tumor invasion, and metastasis formation. In fact, cells react to their mechanical environment modulating their adhesion, cytoskeleton organization, changes of shape, and, consequently, the dynamics of their motility. In order to elucidate the role of extracellular matrix stiffness as a driving force in cancer cell motility/invasion and the effects of ionizing radiations on these processes, we evaluated adhesion and migration as biophysical properties of two different mammary cell lines, over a range of pathophysiological stiffness (1-13 kPa) in a control condition and after the exposure to two different X-ray doses (2 and 10 Gy, photon beams). We concluded that the microenvironment mimicking the normal mechanics of healthy tissue has a radioprotective role on both cell lines, preventing cell motility and invasion. Supraphysiological extracellular matrix stiffness promoted tumor cell motility instead, but also had a normalizing effect on the response to radiation of tumor cells, lowering their migratory capability. This work lays the foundation for exploiting the extracellular matrix-mediated mechanism underlying the response of healthy and tumor cells to radiation treatments and opens new frontiers in the diagnostic and therapeutic use of radiotherapy.

Cell mechanosensing is regulated by substrate strain energy rather than stiffness

The ability of cells to perceive the mechanical identity of extracellular matrix, generally known as mechanosensing, is generally depicted as a consequence of an intricate balance between pulling forces actuated by the actin fibers on the adhesion plaques and the mechanical reaction of the supporting material. However, whether the cell is sensitive to the stiffness or to the energy required to deform the material remains unclear. To address this important issue, here the cytoskeleton mechanics of BALB/3T3 and MC3T3 cells seeded on linearly elastic substrates under different levels of deformation were studied. In particular, the effect of prestrain on cell mechanics was evaluated by seeding cells both on substrates with no prestrain and on substrates with different levels of prestrain. Results indicated that cells recognize the existence of prestrain, exhibiting a stiffer cytoskeleton on stretched material compared to cells seeded on unstretched substrate. Cytoskeleton mechanics of cells seeded on stretched material were, in addition, comparable to those measured after the stretching of the substrate and cells together to the same level of deformation. This observation clearly suggests that cell mechanosensing is not mediated only by the stiffness of the substrate, as widely assumed in the literature, but also by the deformation energy associated with the substrate. Indeed, the clutch model, based on the exclusive dependence of cell mechanics upon substrate stiffness, fails to describe our experimental results. By modifying the clutch model equations to incorporate the dependence on the strain energy, we were able to correctly interpret the experimental evidence.

Biomimetic polycaprolactone-chitosan nanofibrous substrate influenced cell cycle and ECM secretion affect cellular uptake of nanoclusters

Biomimetic cell culture substrates are developed as an alternative to the conventional substrates. They provide necessary biochemical and biophysical cues to the cells from their surrounding environment for their optimal growth, behaviour and physiology. Changes in physiology of cells growing on biomimetic substrate can essentially affect results of in vitro biological experiments such as drug cytotoxicity, nanoparticle internalization or signalling pathways. As majority of ECM proteins are fibrous in nature, nanofibrous scaffolds have more biomimicking properties. Therefore, in this study, we developed ECM mimicking polycaprolactone-chitosan nanofiber substrate and evaluated its effect on cell morphology, proliferation, cell cycle and ECM production. Further, cellular uptake of BSA-AuNCs has been assessed on conventional and biomimetic substrate in order to demonstrate the effect of these events on cellular properties. It was observed that the cells that were grown for 15 days on the nanofibers, had majority of cells in the proliferative phase of cell cycle compared to TCPS. Moreover, these cells showed extensive collagen and fibronectin production. Due to these conditions C3H10T1/2 cells displayed higher cell internalization of BSA-AuNCs. Overall, this study indicates that the nano-topographical and biochemical environment could alter the cell proliferative behaviour and ECM production, which affects the cell internalization of BSA-AuNCs. Also, PCL-chitosan nanofibrous substrate could be a better alternative to TCPS for cell culture studies.