Engineered platelet cell motors for boosted cancer radiosensitization

Design of engineered cells to target and deliver nanodrugs to the hard-to-reach regions has become an exciting research area. However, the limited penetration and retention of cell-based carriers in tumor tissue restricted their therapeutic efficiency. Inspired by the enhanced delivery behavior of mobile micro/nanomotors, herein, urease-powered platelet cell motors (PLT@Au@Urease) capable of active locomotion, tumor targeting, and radiosensitizers delivery were designed for boosting radiosensitization. The engineered platelet cell motors were constructed by in situ synthesis and loading of radiosensitizers gold nanoparticles in platelets, and then conjugation with urease as the engine. Under physiological concentration of urea, thrust around PLT@Au@Urease motors can be generated via the biocatalytic reactions of urease, leading to rapid tumor cell targeting and enhanced cellular uptake of radiosensitizers. Encouragingly, in comparison with engineered PLT without propulsion capability (PLT@Au), the self-propelled PLT@Au@Urease motors could significantly increase intracellular ROS level and exacerbate nuclear DNA damage induced by γ-radiation, resulting in a remarkably high sensitization enhancement rate (1.89) than that of PLT@Au (1.08). In vivo experiments with 4 T1-bearing mice demonstrated that PLT@Au@Urease in combination with radiation therapy possessed good antitumor performance. Such an intelligent cell motor would provide a promising approach to enhance radiosensitization and broaden the applications of cell motor-based delivery systems.

Size transformable organic nanotheranostic agents for NIR-II imaging-guided oncotherapy

Nanotheranostic agents combined the second near-infrared (NIR-II, 1000-1700 nm) fluorescence imaging with phototherapy strategy have attracted tremendous interest. However, the actual efficacy of NIR-II probes could be weakened by their limited accumulation and penetration in tumor tissues. Herein, a size-transformable NIR-II nanotheranostic agent (BBT-HASS@FPMPL NPs) is employed for simultaneously enhanced penetration and retention in deep tumor tissue to realize precise image and effective PTT therapy. BBT-HASS@FPMPL NPs were first formed by using hyaluronic acid (HA) chains and disulfide bonds as stimuli-responsive "lock" to efficiently load conjugated oligomer (BBTN+), and then folic acid (FA) modified polylysine (FPMPL) shell was stacked at the surface by electrostatic interaction. Dual targeting with HA and FA is expected to lead to more selective targeting and better accumulation of BBT-HASS@FPMPL NPs in tumor sites. Simultaneously, obvious particle size reduction and charge reversal can be triggered in acidic tumor microenvironment to achieve deep intratumor filtration through transcytosis. Following tumor penetration, size change was further initiated by overexpressed hyaluronidase and GSH in tumor. Free BBTN+ can be subsequently released from nanoparticles to promote specific intratumor retention, which synergistically enhance photothermal therapeutic efficacy. Owing to sufficient tumor accumulation and deep penetration, the NIR-II emission of BBTN+ could further be used for precise monitoring of subcutaneous tumor progression in mice for 6 days with just one dose injection. We expect that such nanotheranostic platform that combined the high resolution of NIR-II fluorescence with deep tumor penetration and long intratumor retention could be useful for real-time monitoring of tumor process, precise diagnosis, and enhanced phototherapy.

Escherichia coli Nissle 1917-driven microrobots for effective tumor targeted drug delivery and tumor regression

Potent tumor regression remains challenging due to the lack of effective targeted drug delivery into deep tumors as well as the reduced susceptibility of cancer cells to anticancer agents in hypoxic environments. Bacteria-driven drug-delivery systems are promising carriers in overcoming targeting and diffusion limits that are inaccessible for conventional antitumor drugs. In this study, probiotic facultative anaerobe Escherichia coli Nissle 1917 (EcN) was functionalized and formed self-propelled microrobots to actively deliver therapeutic drug and photosensitizer to the deep hypoxic regions of tumors. Doxorubicin (Dox) was firstly modified with cis-aconityl anhydride (CA) and terminal thiol-decorated hydrazone derivative (Hyd-SH) through dual pH-sensitive amide and imine bonds, respectively. The functionalized CA-Dox-Hyd-SH was further coordinated with photosensitizer gold nanorods (AuNRs) and then conjugated to the surface of EcN. The resulting microrobots (EcN-Dox-Au) inherited the mobility characteristics and bioactivity of native EcN. Upon the irradiation of NIR laser, the microrobots exhibited enhanced tumor accumulation and penetration into the deep hypoxia tumor site. Strikingly, after 21 days of treatment with EcN-Dox-Au formulations, complete tumor regression was achieved without relapse for at least 53 days. This self-propelled strategy utilizing bacteria-driven microrobots provides a promising paradigm for enhancing drug penetration and elevating chemosensitivity, resulting in a superior antitumor effect. STATEMENT OF SIGNIFICANCE: Self-propelled Escherichia coli Nissle 1917 (EcN) - mediated microrobots are functionalized to co-deliver therapeutic drugs and photosensitizers to the deep tumor site. Anti-tumor drug doxorubicin (Dox) was modified through dual pH-sensitive bonds on both terminals and then linked with EcN and photosensitizer gold nanorods (AuNRs) to realize tumor microenvironment acidic pH-responsive drug release. Upon irradiation with a NIR laser near the tumor site, AuNRs produced a photothermal effect which realized the superficial tumor thermal ablation and increased the permeability of the tumor cell membrane to facilitate the penetration of microrobots. Moreover, the deep penetration of microrobots also enhanced the susceptibility of the cancer cells to Dox, and realized the complete tumor regression in the established breast cancer-bearing mice without recurrence using a lower dose of drug regimen.

Fluorescence-free bis(dithiolene)nickel dyes for surface-enhanced resonance Raman imaging in the second near-infrared window

Second near-infrared window (NIR-II, 1000-1700 nm) imaging is one of the foremost optical imaging techniques. However, surface-enhanced Raman scattering (SERS)-based research in this optical region remains in its infancy, mainly because of a lack of suitable NIR-II Raman reporters. Herein, we report the first example of a nickel dithiolene complex as a NIR-II resonance Raman reporter with intense long wavelength absorption (ε = 9.58 × 104 m-1 cm-1 at 1007 nm), fluorescence-free features and ultrahigh affinity to noble metal surfaces with its eight sulfur atoms. Surface-enhanced resonance Raman scattering nanoprobes constructed with such reporters enable high contrast and highly photostable lymph node imaging far superior to that possible with existing NIR-I and NIR-II SERS nanoprobes. The developed NIR-II nanoprobes allow deep optical penetration (8 mm) as well as in vivo SERS detection of deep-seated microtumors in mice.

Artesunate carriers induced ferroptosis to overcome biological barriers for anti-cancer

Artesunate (ART) has potent anticancer activity but it suffers from poor stability and low bioavailability in vivo due to the special endoperoxide moiety in the molecules. In this work, we fabricated programmable enzyme/reactive oxygen species (ROS) responsive ART complex carriers with size and charge adaptive regulation in order to improve stability and overcome biochemical hurdles of solid tumor. The complex carries (ART/AA-PAMAM@HA) were created by electrostatic interaction between dendrimer-ART/arachidonic acid (AA) (ART/AA-PAMAM) and hyaluronic acid (HA), which can proactively penetrate deeply into tumors and selective drug release. Specifically, ART induced Fenton reaction and produced a mass of ROS and lipid peroxides (LPO), leading to the depressing of GSH level and glutathione peroxidase 4 (GPX4) activity. Meanwhile, exogenous AA further promoted the accumulation of LPO by cascade regulating ferroptosis pathway. In the anti-tumor efficacy in vivo, the tumor inhibition ratio was achieved to 46.92%. This work shows a new anti-tumor strategy triggering ferroptosis via regulating redox homeostasis.

Prospects for hypoxia-based drug delivery platforms for the elimination of advanced metastatic tumors: From 3D modeling to clinical concepts

Hypoxia is a unique characteristic of the solid tumor microenvironment. Hypoxia contributes to multi-drug resistance, metastasis and cancer relapse through numerous molecular pathways, but at the same time provides an opportunity for the development of novel drugs or modalities specifically targeting hypoxic tumor regions. Given the high significance of tumor hypoxia in therapeutic results, we here discuss a variety of hypoxia-adopted strategies, and their potential and utility in the treatment of deep-seated hypoxic tumor cells. We discuss the merits and demerits of these approaches, as well as their combination with other approaches such as photodynamic therapy. We also survey the currently available 3D hypoxia modeling systems, in particular organoid-based microfluidics. Finally, we discuss the potential and the current status of preclinical tumor hypoxia approaches in clinical trials for advanced cancer. We believe that multi-modal imaging and therapeutic hypoxia adopted drug delivery platforms could provide better efficacy and safety profiles, and more importantly personalized therapy. Determining the hypoxia status of tumors could offer a second chance for the clinical translation of hypoxia-based agents, such as hypoxia activated prodrugs (HAPs) from bench to bedside.

Nanodevices for deep cartilage penetration

Osteoarthritis (OA) is a degenerative joint disease and is the main cause of chronic pain and functional disability in adults. Articular cartilage is a hydrated soft tissue that is composed of normally quiescent chondrocytes at a low density, a dense network of collagen fibrils with a pore size of 60-200 nm, and aggrecan proteoglycans with high-density negative charge. Although certain drugs, nucleic acids, and proteins have the potential to slow the progression of OA and restore the joints, these treatments have not been clinically applied owing to the lack of an effective delivery system capable of breaking through the cartilage barrier. Recently, the development of nanotechnology for delivery systems renders new ideas and treatment methods viable in overcoming the limited penetration. In this review, we focus on current research on such applications of nanotechnology, including exosomes, protein-based cationic nanocarriers, cationic liposomes/solid lipid nanoparticles, amino acid-based nanocarriers, polyamide derivatives-based nanocarriers, manganese dioxide, and carbon nanotubes. Exosomes are the smallest known nanoscale extracellular vesicles, and they can quickly deliver nucleic acids or proteins to the required depth. Through electrostatic interactions, nanocarriers with appropriate balance in cationic property and particle size have a strong ability to penetrate cartilage. Although substantial preclinical evidence has been obtained, further optimization is necessary for clinical transformation. STATEMENT OF SIGNIFICANCE: The dense cartilage matrix with high-negative charge was associated with reduced therapeutic effect in osteoarthritis patients with deep pathological changes. However, a systematic review in nanodevices for deep cartilage penetration is still lacking. Current approaches to assure penetration of nanosystems into the depth of cartilage were reviewed, including nanoscale extracellular vesicles from different cell lines and nanocarriers with appropriate balance in cationic property and size particle. Moreover, nanodevices entering clinical trials and further optimization were also discussed, providing important guiding significance to future research.

Smart hypoxia-responsive transformable and charge-reversible nanoparticles for the deep penetration and tumor microenvironment modulation of pancreatic cancer

The compact extracellular matrix (ECM) of pancreatic ductal adenocarcinoma (PDAC) is the major physical barrier that hinders the delivery of anti-tumor drugs, leading to strong inherent chemotherapy resistance as well as establishing an immunosuppressive tumor microenvironment (TME). However, forcibly destroying the stroma barrier would break the balance of delicate signal transduction and dependence between tumor cells and matrix components. Uncontrollable growth and metastasis would occur, making PDAC more difficult to control. Hence, we design and construct an aptamer-decorated hypoxia-responsive nanoparticle s(DGL)n@Apt co-loading gemcitabine monophosphate and STAT3 inhibitor HJC0152. This nanoparticle can reverse its surficial charge in the TME, and reduce the size triggered by hypoxia. The released ultra-small DGL particles loading gemcitabine monophosphate exhibit excellent deep-tumor penetration, chemotherapy drugs endocytosis promotion, and autophagy induction ability. Meanwhile, HJC0152 inhibits overactivated STAT3 in both tumor cells and tumor stroma, softens the stroma barrier, and reeducates the TME into an immune-activated state. This smart codelivery strategy provides an inspiring opportunity in PDAC treatment.

Autophagy responsive intra-intercellular delivery nanoparticles for effective deep solid tumor penetration

Deep tumor cells (cells in the center of solid tumors) play a crucial role in drug tolerance, metastasis, recurrence and microenvironment immune suppression. However, their deep location endows them with an untouched abdomen and makes them refractory to current treatments. Herein, we exploited the characteristic of higher autophagy in deep tumor cells than in superficial tumor cells and designed autophagy-responsive multifunctional nanoparticles (PGN) to enhance drug accumulation in deep tumor cells. PGNs were prepared by densely coating poly (lactic-co-glycolic acid) (PLGA) with cationic autophagy-responsive cell-penetrating peptide (GR9) and anionic 2,3-dimethylmaleic anhydride (DMA)-modified DSPE-PEG. The suitable nanoparticle size (122.4 nm) and charge-neutral surface (0.21 mV) of the NPs enabled long blood circulation. The hydrolysis of surface-anchored anionic DMA in the acidic microenvironment led to the exposure of the GR9 peptide and enhance tumor penetration. Once the PGN arrived in deep tumor cells with strong autophagy, GR9 was cut off by an autophagy shear enzyme, and the nanoparticles remained in the cells to undergo degradation. Furthermore, we prepared docetaxel (DTX) and chloroquine (CQ) loaded d-PGN. CQ inhibits autophagosome fusion with lysosomes, resulting in autophagosome accumulation, which further enhances the sensitivity of d-PGN to autophagy and their deep tumor retention. In vivo experiments showed that drug-loaded d-PGN achieved excellent antitumor efficacy with a peak inhibition rate of 82.1%. In conclusion, autophagy-responsive multifunctional nanoparticles provide a novel potential strategy for solid tumor treatment.

Microfluidics-Assisted Engineering of pH/Enzyme Dual-Activatable ZIF@Polymer Nanosystem for Co-Delivery of Proteins and Chemotherapeutics with Enhanced Deep-Tumor Penetration

The impermeable barriers of solid tumors restrict the co-delivery of protein-based drugs and chemotherapeutics for cancer treatment. Therefore, we developed a ZIF-DOX/RA@DG nanosystem that encapsulates ribonuclease A (RA) and doxorubicin (DOX) in a zeolitic imidazolate framework (ZIF-8) core, with a dextran-based coating (DG). The nanosystem exhibits dual-responsiveness due to γ-glutamyl transpeptidase-activatable cationization and acidic microenvironment-triggered degradation. The DG-coating process was achieved using a microfluidic approach, which stabilized the polymer responsiveness, ZIF-8-based structure, and bioactivity of the encapsulated therapeutics. In vivo results confirmed that the nanosystem could co-deliver RA and DOX to deep impermeable lesions with a synergistic anticancer therapeutic effects. Such a multi-drug delivery system based on an intelligent-responsive design and a microfluidics-assisted synthesis strategy shows great clinical prospects.

High-resolution photoacoustic microscopy with deep penetration through learning

Optical-resolution photoacoustic microscopy (OR-PAM) enjoys superior spatial resolution and has received intense attention in recent years. The application, however, has been limited to shallow depths because of strong scattering of light in biological tissues. In this work, we propose to achieve deep-penetrating OR-PAM performance by using deep learning enabled image transformation on blurry living mouse vascular images that were acquired with an acoustic-resolution photoacoustic microscopy (AR-PAM) setup. A generative adversarial network (GAN) was trained in this study and improved the imaging lateral resolution of AR-PAM from 54.0 µm to 5.1 µm, comparable to that of a typical OR-PAM (4.7 µm). The feasibility of the network was evaluated with living mouse ear data, producing superior microvasculature images that outperforms blind deconvolution. The generalization of the network was validated with in vivo mouse brain data. Moreover, it was shown experimentally that the deep-learning method can retain high resolution at tissue depths beyond one optical transport mean free path. Whilst it can be further improved, the proposed method provides new horizons to expand the scope of OR-PAM towards deep-tissue imaging and wide applications in biomedicine.

Rapid pH-responsive self-disintegrating nanoassemblies balance tumor accumulation and penetration for enhanced anti-breast cancer therapy

The dilemma of tumor accumulation and deep penetration has always been a barrier in antitumor therapy. Stimuli-responsive size changeable drug delivery systems provide possible solutions. Nevertheless, the low size-shrinkage efficiency limited the antitumor effects. In this study, an instant pH-responsive size shrinkable nanoassemblies named self-aggregated DOX@HA-CD (SA-DOX@HA-CD) was formulated using small-sized hyaluronic acid modified carbon dots (HA-CD) as monomers, which could self-aggregate into raspberry-like structure via hydrophobicity force in neutral pH and rapidly disassemble into shotgun-like DOX-loaded CD monomer in simulated tumor microenvironment (pH 6.5), owing to the transformation in electrical charge and hydrophobicity/hydrophilicity of this system. The transmission electron microscopy showed that the clustered SA-DOX@HA-CD had a diameter of ~150 nm, and thoroughly disassembled into ~30 nm nanoparticles in response to acidic environment. The disassemble efficiency was approximately 100%. Attributed to this property, SA-DOX@HA-CD led to enhanced cellular internalization and accumulation in 4T1 cells in simulated tumor microenvironment, as well as deep tumor penetration in 3D tumor spheroid model. Besides, the imine bond between DOX and HA-CD endowed DOX with pH-responsive release profile in the acidic lysosome environment. Furthermore, in the orthotopic 4T1 tumor-bearing mouse model, SA-DOX@HA-CD demonstrated higher tumor accumulation than non-aggregated DOX-HA-CD. Meanwhile, in response to the acid tumor microenvironment, the dissociated DOX-HA achieved deep tumor penetration, which consequently resulted in 2.5-fold higher antitumor efficiency. The formulation of self-aggregated SA-DOX@HA-CD provides a simple and effective alternative to prepare pH-responsive size-shrinkable nanodrug delivery systems. STATEMENT OF SIGNIFICANCE: The heterogeneity of tumor vasculature and the high tumor interstitial pressure lead to the barriers in tumor accumulation and deep penetration, which calls for opposite properties (e.g. size) of drug delivery systems. To address this dilemma, various size changeable nanoparticles have been developed utilizing special features of tumor microenvironment, such as pH, enzyme and reactive oxygen species. Nevertheless, the current strategies face the problems of incomplete hydrolysis of chemical bonds or insufficient enzyme degradation, which result in only partial size shrinkage, hindering the tumor deep penetration effects. Here we developed a self-assembled nanocluster, which could respond to acidic pH rapidly and thoroughly disassemble into small nanodots due to the alteration of hydrophobicity/hydrophilicity/charge, leading to approximately 100% dissociation. This strategy provides a new concept for design of size changeable drug delivery systems.

Noninvasively immunogenic sonodynamic therapy with manganese protoporphyrin liposomes against triple-negative breast cancer

Sonodynamic therapy (SDT) is a promising approach for tumor treatment because of the noninvasion, and future would be perfect while it activates systemic immune responses through deep penetration to effectively avoid tumor recurrence. Here, a multifunctional nanosonosensitizer system (FA-MnPs) is designed by encapsulating manganese-protoporphyrin (MnP) into folate-liposomes. The nanoparticles of FA-MnPs not only exhibit excellent depth-responsive SDT but also simultaneously activate SDT-mediated immune response. Under US irradiation, FA-MnPs show the high acoustic intensity in mimic tissue up to 8 cm depth and generate amount of singlet oxygen (¹O₂). Density functional theory (DFT) calculations reveal that metal coordination in MnP has enhanced the US response ability. The good depth-responsed SDT of FA-MnPs efficiently suppresses the growth of not only the superficial tumors but also the deep lesion in the triple-negative breast cancer (TNBC) mice model. Importantly, FA-MnPs-induced SDT further re-polarizes immunosuppressive M2 macrophages to antitumor M1 macrophages, and elicits immunogenic cell death (ICD) to activate dendritic cells, T lymphocytes, and natural killercells (NK), which consequently trigger the antitumor immune, contributing to the tumor growth inhibition. This study put forward an idea for curing deep-seated and metastatic tumors through noninvasively depth-irradiated immunogenic SDT by reasonably designing multifunctional sonosensitizers.

Rational collaborative ablation of bacterial biofilms ignited by physical cavitation and concurrent deep antibiotic release

Bacteria biofilm has extracellular polymeric substances to protect bacteria from external threats, which is a stubborn problem for human health. Herein, a kind of gasifiable nanodroplet is fabricated to ablate Staphylococcus aureus (S. aureus) biofilm. Upon NIR pulsed laser irradiation, the nanodroplets can gasify to generate destructive gas shockwave, which further potentiates initial acoustic cavitation effect, thus synergistically disrupting the protective biofilm and killing resident bacteria. More importantly, the gasification can further promote antibiotic release in deep biofilm for residual bacteria eradication. The nanodroplets not only exhibit deep biofilm penetration capacity and high potency to ablate biofilms, but also good biocompatibility without detectable side effects. In vivo mouse implant model indicates that the nanodroplets can accumulate at the S. aureus infected implant sites. Upon pulsed laser treatment, the nanodroplets efficiently eradicate bacteria biofilm in implanted catheter by synergistic contribution of gas shockwave-enhanced cavitation and deep antibiotic release. Current phase changeable nanodroplets with synergistic physical and chemical therapeutic modalities are promising to combat complex bacterial biofilms with drug resistance, which provides an alternative visual angle for biofilm inhibition in biomedicine.

Phagocyte-membrane-coated and laser-responsive nanoparticles control primary and metastatic cancer by inducing anti-tumor immunity

To achieve safe and effective antitumor immunity, we constructed the M1-macrophage-membrane-coated nanoparticles [(C/I)BP@B-A(D)&M1m] having laser-responsive, size-changeable, on-demand drug release and prolonged circulation retention properties. (C/I)BP@B-A(D)&M1m delayed clearance by the phagocytic system and homed to tumor efficiently. Upon 650 nm laser irradiation, the hydrophobic core of the PEGylated bilirubin nanoparticles (BP) got disrupted, releasing small-sized deep-penetrating B-A(D) particles, photosensitive chlorin e6 (C), and tolerance-inducing indoleamine 2,3-dioxygenase inhibitor, indoximode (I). Treatment-induced immunogenic cell death and antitumor immunity, suppressing primary tumor growth in both 4T1 and B16F10 models without causing any adverse effects. Most importantly, it inhibited primary tumor recurrence as well as metastasis. Thus, this study provides a promising combinatorial strategy to trigger antitumor immunity in malignancies.

iRGD-decorated red shift emissive carbon nanodots for tumor targeting fluorescence imaging

Carbon nanodots (CDs) have been exhibiting increasing applications owing to their luminescence properties and biocompatibility as imaging probes in diagnosis. However, poor tumor targeting and penetration of CDs is still the biggest challenge limiting their tumor imaging efficacy. To improve the tumor targeting and penetration efficiency of CDs, we developed an active tumor targeting imaging system by simply fabricating a tumor-homing penetration peptide iRGD (CRGDKGPDC) to red shift emissive CDs (iRGD-CDs) with a physical method. Particularly, iRGD-CDs showed a small size and red shift fluorescence signals as CDs, which made iRGD-CDs suitable for in vivo fluorescence imaging. iRGD-CDs showed higher cellular uptake in vitro, while presented higher penetration and accumulation in tumor tissue in vivo, leading to better tumor imaging efficacy. In conclusion, decoration with iRGD could significantly increase the permeability of CDs in tumor vessels and tumor tissue, generating more CDs leaking out from tumor vasculature, consequently improving the sensitivity of tumor imaging.

The multilayer nanoparticles for deep penetration of docetaxel into tumor parenchyma to overcome tumor microenvironment

Deep penetration of the anticancer drug, docetaxel (DTX), into tumor parenchyma was demonstrated to achieve improved chemotherapy. For this purpose, a multistage nanostructure was designed and characterized using the multilayer nanoparticles (NPs). The multilayer NPs had a core/shell structure. The core was composed of the DTX-loaded Pluronic NPs (diameter: 12nm) that were transferred into the inner side of vesicles to form the vesicle NPs. Förster resonance energy transfer (FRET) in the NPs was observed to verify the incorporation of the DTX-loaded Pluronic NPs into the inner side of the vesicles during the formation of the vesicle NPs. Subsequently, the vesicle NPs were stabilized through Pluronic-lipid bilayer interaction to form the multilayer NPs. To examine the morphology and size distribution of the multilayer NPs, transmittance electron microscopy and dynamic light scattering were used. In vitro release behavior and toxicity were observed to verify the functionality of the multilayer NPs as nanocarriers for cancer therapy. Multistage functionality was evaluated by cellular uptake and tissue distribution behaviors of the multilayer NPs. The biodistribution of the multilayer NPs and their antitumor efficacy were also observed to understand the role of multistage functionality for improved chemotherapy.

Failure properties of vena cava tissue due to deep penetration during filter insertion

In this work, we use an in-vitro mechanical test to explore the resistance of biaxially stretched vena cava tissue against deep perforation and a methodology which integrates experimental and numerical modeling to identify constitutive fracture properties of the vena cava. Six sheep vena cava were harvested just after killing, and cyclic uniaxial tension tests in longitudinal and circumferential directions and biaxial deep penetration tests were performed. After that, we use a nonlinear finite element model to simulate in vitro penetration of the cava tissue in order to fit the fracture properties under penetration of the vena cava by defining a cohesive fracture zone. An iterative process was developed in order to fit the fracture properties of the vena cava using the previously obtained experimental results. The proposed solutions were obtained with fracture energy of 0.22 or 0.33 N/mm. In comparison with the experimental data, the simulation using [Formula: see text], [Formula: see text], and [Formula: see text] parameters ([Formula: see text]) is in good agreement with results from penetration experiments of cava tissue. It is noticeable that the parameter estimation process of the fracture behavior is more accurate than the estimation process of the elastic behavior for the toe region of the curve.