Lorenzo Vannozzi

@santannapisa.it

The BioRobotics Institute
Scuola Superiore Sant'Anna

RESEARCH, TEACHING, or OTHER INTERESTS

Biomedical Engineering

38

Scopus Publications

Scopus Publications

  • Visible light-mediated cross-linking of injectable gellan gum hydrogels embedding human chondrocytes
    Diego Trucco, Lorenzo Vannozzi, Elena Gabusi, Enrico Lenzi, Cristina Manferdini, Alessia Bacci, Liliana Agresti, Maria Rosaria Pascale, Sandra Cristino, Gina Lisignoli,et al.

    Elsevier BV

  • Convolutional neural networks applied to microtomy: Identifying the trimming-end cutting routine on paraffin-embedded tissue blocks
    Lorena Guachi-Guachi, Jacopo Ruspi, Paola Scarlino, Aliria Poliziani, Sabrina Ciancia, Dario Lunni, Gabriele Baldi, Andrea Cavazzana, Alessandra Zucca, Marco Bellini,et al.

    Elsevier BV

  • Soft Perfusable Device to Culture Skeletal Muscle 3D Constructs in Air
    Federica Iberite, Marco Piazzoni, Daniele Guarnera, Francesco Iacoponi, Silvia Locarno, Lorenzo Vannozzi, Giacomo Bolchi, Federica Boselli, Irini Gerges, Cristina Lenardi,et al.

    American Chemical Society (ACS)
    Devices for in vitro culture of three-dimensional (3D) skeletal muscle tissues have multiple applications, including tissue engineering and muscle-powered biorobotics. In both cases, it is crucial to recreate a biomimetic environment by using tailored scaffolds at multiple length scales and to administer prodifferentiative biophysical stimuli (e.g., mechanical loading). On the contrary, there is an increasing need to develop flexible biohybrid robotic devices capable of maintaining their functionality beyond laboratory settings. In this study, we describe a stretchable and perfusable device to sustain cell culture and maintenance in a 3D scaffold. The device mimics the structure of a muscle connected to two tendons: Tendon–Muscle–Tendon (TMT). The TMT device is composed of a soft (E ∼ 6 kPa) porous (pore diameter: ∼650 μm) polyurethane scaffold, encased within a compliant silicone membrane to prevent medium evaporation. Two tendon-like hollow channels interface the scaffold with a fluidic circuit and a stretching device. We report an optimized protocol to sustain C2C12 adhesion by coating the scaffold with polydopamine and fibronectin. Then, we show the procedure for the soft scaffold inclusion in the TMT device, demonstrating the device’s ability to bear multiple cycles of elongations, simulating a protocol for cell mechanical stimulation. By using computational fluid dynamic simulations, we show that a flow rate of 0.62 mL/min ensures a wall shear stress value safe for cells (<2 Pa) and 50% of scaffold coverage by an optimal fluid velocity. Finally, we demonstrate the effectiveness of the TMT device to sustain cell viability under perfusion for 24 h outside of the CO2 incubator. We believe that the proposed TMT device can be considered an interesting platform to combine several biophysical stimuli, aimed at boosting skeletal muscle tissue differentiation in vitro, opening chances for the development of muscle-powered biohybrid soft robots with long-term operability in real-world environments.

  • A Novel Approach for Multiple Material Extrusion in Arthroscopic Knee Surgery
    Tommaso Mazzocchi, Daniele Guarnera, Diego Trucco, Francesco Rocco Restaino, Lorenzo Vannozzi, Alessio Siliberto, Gina Lisignoli, Stefano Zaffagnini, Alessandro Russo, and Leonardo Ricotti

    Springer Science and Business Media LLC
    AbstractArticular cartilage defects and degenerative diseases are pathological conditions that cause pain and the progressive loss of joint functionalities. The most severe cases are treated through partial or complete joint replacement with prostheses, even if the interest in cartilage regeneration and re-growth methods is steadily increasing. These methods consist of the targeted deposition of biomaterials. Only a few tools have been developed so far for performing these procedures in a minimally invasive way. This work presents an innovative device for the direct deposition of multiple biomaterials in an arthroscopic scenario. The tool is easily handleable and allows the extrusion of three different materials simultaneously. It is also equipped with a flexible tip to reach remote areas of the damaged cartilage. Three channels are arranged coaxially and a spring-based dip-coating approach allows the fabrication and assembly of a bendable polymeric tip. Experimental tests were performed to characterize the tip, showing the ability to bend it up to 90° (using a force of ~ 1.5 N) and to extrude three coaxial biomaterials at the same time with both tip straight and tip fully bent. Rheometric analysis and fluid-dynamic computational simulations were performed to analyze the fluids’ behavior; the maximum shear stresses were observed in correspondence to the distal tip and the channel convergence chamber, but with values up to ~ 1.2 kPa, compatible with a safe extrusion of biomaterials, even laden with cells. The cells viability was assessed after the extrusion with Live/Dead assay, confirming the safety of the extrusion procedures. Finally, the tool was tested arthroscopically in a cadaveric knee, demonstrating its ability to deliver the biomaterial in different areas, even ones that are typically hard-to-reach with traditional tools.

  • Ultrasound Stimulation of Piezoelectric Nanocomposite Hydrogels Boosts Chondrogenic Differentiation in Vitro, in Both a Normal and Inflammatory Milieu
    Leonardo Ricotti, Andrea Cafarelli, Cristina Manferdini, Diego Trucco, Lorenzo Vannozzi, Elena Gabusi, Francesco Fontana, Paolo Dolzani, Yasmin Saleh, Enrico Lenzi,et al.

    American Chemical Society (ACS)
    The use of piezoelectric nanomaterials combined with ultrasound stimulation is emerging as a promising approach for wirelessly triggering the regeneration of different tissue types. However, it has never been explored for boosting chondrogenesis. Furthermore, the ultrasound stimulation parameters used are often not adequately controlled. In this study, we show that adipose-tissue-derived mesenchymal stromal cells embedded in a nanocomposite hydrogel containing piezoelectric barium titanate nanoparticles and graphene oxide nanoflakes and stimulated with ultrasound waves with precisely controlled parameters (1 MHz and 250 mW/cm2, for 5 min once every 2 days for 10 days) dramatically boost chondrogenic cell commitment in vitro. Moreover, fibrotic and catabolic factors are strongly down-modulated: proteomic analyses reveal that such stimulation influences biological processes involved in cytoskeleton and extracellular matrix organization, collagen fibril organization, and metabolic processes. The optimal stimulation regimen also has a considerable anti-inflammatory effect and keeps its ability to boost chondrogenesis in vitro, even in an inflammatory milieu. An analytical model to predict the voltage generated by piezoelectric nanoparticles invested by ultrasound waves is proposed, together with a computational tool that takes into consideration nanoparticle clustering within the cell vacuoles and predicts the electric field streamline distribution in the cell cytoplasm. The proposed nanocomposite hydrogel shows good injectability and adhesion to the cartilage tissue ex vivo, as well as excellent biocompatibility in vivo, according to ISO 10993. Future perspectives will involve preclinical testing of this paradigm for cartilage regeneration.

  • A novel concept of steerable catheters actuated by muscle cells: the BioMeld project


  • Injectable gelatin-based photocurable fiber-reinforced hydrogel for the treatment of osteochondral defects


  • A Novel Steerable Catheter Controlled with a Biohybrid Actuator: A Feasibility Study
    Carlotta Salvatori, Diego Trucco, Ignazio Niosi, Leonardo Ricotti, and Lorenzo Vannozzi

    Springer Nature Switzerland
    AbstractTargeted therapies allow increasing the efficacy of treatments for several diseases, including cancer. The release of drugs or chemicals directly in the site of interest will be beneficial for maximizing the therapy and minimize side effects.Here, we report the concept and a preliminary analysis of an innovative intravascular steerable catheter guided by an on-board biohybrid actuator, aiming to release drugs into deep and tortuous regions within the cardiovascular systems. The catheter performance has been estimated through analytical and numerical analyses, varying catheter diameter, wall thickness, and actuator force. Results show how larger catheter deflections can be obtained with a smaller outer diameter and decreasing wall thickness. Besides, improved outcomes can be achieved by applying the biohybrid actuator distant from the catheter tip extremity and maximizing the magnitude of the applied forces. Despite the need to further improve the performance of this concept (e.g., by decreasing material stiffness), these preliminary results show great promise in view of future experimentation of such kind of actuation to drive microcatheters through the cardiovascular network.

  • Primers for the Adhesion of Gellan Gum-Based Hydrogels to the Cartilage: A Comparative Study
    Diego Trucco, Laura Riacci, Lorenzo Vannozzi, Cristina Manferdini, Lorenzo Arrico, Elena Gabusi, Gina Lisignoli, and Leonardo Ricotti

    Wiley
    AbstractA stable adhesion to the cartilage is a crucial requisite for hydrogels used for cartilage regeneration. Indeed, a weak interface between the tissue and the implanted material may produce a premature detachment and thus the failure of the regeneration processes. Fibrin glue, cellulose nanofibers and catecholamines have been proposed in the state‐of‐the‐art as primers to improve the adhesion. However, no studies focused on a systematic comparison of their performance. This work aims to evaluate the adhesion strength between ex vivo cartilage specimens and polysaccharide hydrogels (gellan gum and methacrylated gellan gum), by applying the mentioned primers as intermediate layer. Results show that the fibrin glue and the cellulose nanofibers improve the adhesion strength, while catecholamines do not guarantee reaching a clinically acceptable value. Stem cells embedded in gellan gum hydrogels reduce the adhesion strength when fibrin glue is used as a primer, being anyhow still sufficient for in vivo applications.

  • Modeling Self-Rollable Elastomeric Films for Building Bioinspired Hierarchical 3D Structures
    Lorenzo Vannozzi, Alessandro Lucantonio, Arturo Castillo, Antonio De Simone, and Leonardo Ricotti

    MDPI AG
    In this work, an innovative model is proposed as a design tool to predict both the inner and outer radii in rolled structures based on polydimethylsiloxane bilayers. The model represents an improvement of Timoshenko’s formula taking into account the friction arising from contacts between layers arising from rolling by more than one turn, hence broadening its application field towards materials based on elastomeric bilayers capable of large deformations. The fabricated structures were also provided with surface topographical features that would make them potentially usable in different application scenarios, including cell/tissue engineering ones. The bilayer design parameters were varied, such as the initial strain (from 20 to 60%) and the bilayer thickness (from 373 to 93 µm). The model matched experimental data on the inner and outer radii nicely, especially when a high friction condition was implemented in the model, particularly reducing the error below 2% for the outer diameter while varying the strain. The model outperformed the current literature, where self-penetration is not excluded, and a single value of the radius of spontaneous rolling is used to describe multiple rolls. A complex 3D bioinspired hierarchical elastomeric microstructure made of seven spirals arranged like a hexagon inscribed in a circumference, similar to typical biological architectures (e.g., myofibrils within a sarcolemma), was also developed. In this case also, the model effectively predicted the spirals’ features (error smaller than 18%), opening interesting application scenarios in the modeling and fabrication of bioinspired materials.

  • Piezoelectric nanocomposite bioink and ultrasound stimulation modulate early skeletal myogenesis
    Claudia Paci, Federica Iberite, Lorenzo Arrico, Lorenzo Vannozzi, Paola Parlanti, Mauro Gemmi, and Leonardo Ricotti

    Royal Society of Chemistry (RSC)
    A cell-laden alginate/Pluronic-based bioink doped with BaTiO3 piezoelectric nanoparticles (BTNPs) was investigated. BTNPs promoted myogenic differentiation and the synergy with ultrasound boosted the expression of MYOD1, MYOG, and MYH2 genes.

  • RGD-Functionalized Hydrogel Supports the Chondrogenic Commitment of Adipose Mesenchymal Stromal Cells
    Cristina Manferdini, Diego Trucco, Yasmin Saleh, Elena Gabusi, Paolo Dolzani, Enrico Lenzi, Lorenzo Vannozzi, Leonardo Ricotti, and Gina Lisignoli

    MDPI AG
    Articular cartilage is known to have limited intrinsic self-healing capacity when a defect or a degeneration process occurs. Hydrogels represent promising biomaterials for cell encapsulation and injection in cartilage defects by creating an environment that mimics the cartilage extracellular matrix. The aim of this study is the analysis of two different concentrations (1:1 and 1:2) of VitroGel® (VG) hydrogels without (VG-3D) and with arginine-glycine-aspartic acid (RGD) motifs, (VG-RGD), verifying their ability to support chondrogenic differentiation of encapsulated human adipose mesenchymal stromal cells (hASCs). We analyzed the hydrogel properties in terms of rheometric measurements, cell viability, cytotoxicity, and the expression of chondrogenic markers using gene expression, histology, and immunohistochemical tests. We highlighted a shear-thinning behavior of both hydrogels, which showed good injectability. We demonstrated a good morphology and high viability of hASCs in both hydrogels. VG-RGD 1:2 hydrogels were the most effective, both at the gene and protein levels, to support the expression of the typical chondrogenic markers, including collagen type 2, SOX9, aggrecan, glycosaminoglycan, and cartilage oligomeric matrix protein and to decrease the proliferation marker MKI67 and the fibrotic marker collagen type 1. This study demonstrated that both hydrogels, at different concentrations, and the presence of RGD motifs, significantly contributed to the chondrogenic commitment of the laden hASCs.

  • Monolithic Three-Dimensional Functionally Graded Hydrogels for Bioinspired Soft Robots Fabrication
    Marco Piazzoni, Elisa Piccoli, Lorenzo Migliorini, Edoardo Milana, Federica Iberite, Lorenzo Vannozzi, Leonardo Ricotti, Irini Gerges, Paolo Milani, Claudia Marano,et al.

    Mary Ann Liebert Inc
    Bioinspired soft robotics aims at reproducing the complex hierarchy and architecture of biological tissues within artificial systems to achieve the typical motility and adaptability of living organisms. The development of suitable fabrication approaches to produce monolithic bodies provided with embedded variable morphological and mechanical properties, typically encountered in nature, is still a technological challenge. Here we report on a novel manufacturing approach to produce three-dimensional functionally graded hydrogels (3D-FGHs) provided with a controlled porosity gradient conferring them variable stiffness. 3D-FGHs are fabricated by means of a custom-designed liquid foam templating (LFT) technique, which relies on the inclusion of air bubbles generated by a blowing agent into the monomer-based template solution during ultraviolet-induced photopolymerization. The 3D-FGHs' apparent Young's modulus ranges from 0.37 MPa (bulky hydrogel region) to 0.09 MPa (highest porosity region). A fish-shaped soft swimmer is fabricated to demonstrate the feasibility of the LFT technique to produce bioinspired robots. Mobility tests show a significant improvement in terms of swimming speed when the robot is provided with a graded body. The proposed manufacturing approach constitutes an enabling solution for the development of macroscopic functionally graded hydrogel-based structures usable in biomimetic underwater soft robotics applications.

  • Thermal Analysis of Paraffin-Embedded Tissue Blocks for Anatomic Pathology Processes
    Sabrina Ciancia, Alessandro Lucantonio, Lorenzo Vannozzi, Gian Andrea Pedrazzini, and Leonardo Ricotti

    ASME International
    AbstractWe analyze temperature dynamics in anatomic pathology samples to identify the most efficient refrigeration method and to predict the time available for optimal sectioning before sample heating, thus getting appropriate information for a correct diagnosis by anatomopathologists. A thermal finite element (FE) analysis was carried out with comsolmultiphysics to evaluate temperature variations in paraffin-embedded tissues, i.e., muscle, bone and fat, and the corresponding thermal stresses. Experiments with different tissues and thermocouple-based measurements allowed validating the FE simulations. Simulations allowed to estimate the time needed to bring the sample at the optimal temperature for sectioning (−8 to −4 °C) in different conditions: refrigeration on a cold plate, refrigeration in a cooled environment, and refrigeration in an environment with forced convection. Among the three cooling methods tested, the forced convection at −20 °C and with an air-flow speed of 5 m/s resulted in the shortest cooling time. As compared to the other methods, thermal stresses can be modulated by varying the air-flow speed. For the different conditions, the time needed for the surface of the tissue block to exit from a temperature corresponding to an optimal cutting, when leaving the sample exposed to room temperature after refrigeration, ranged from 12 to 310 s. We quantify the time needed to adequately refrigerate paraffin-embedded tissue samples and the time available before they leave the optimal temperature window for sectioning. We also evaluate the maximum stress attained in the paraffin block during the cooling and the heating transients. This information will help optimize anatomic pathology processes.

  • Graphene oxide and reduced graphene oxide nanoflakes coated with glycol chitosan, propylene glycol alginate, and polydopamine: Characterization and cytotoxicity in human chondrocytes
    Lorenzo Vannozzi, Enrico Catalano, Madina Telkhozhayeva, Eti Teblum, Alina Yarmolenko, Efrat Shawat Avraham, Rajashree Konar, Gilbert Daniel Nessim, and Leonardo Ricotti

    MDPI AG
    Recently, graphene and its derivatives have been extensively investigated for their interesting properties in many biomedical fields, including tissue engineering and regenerative medicine. Nonetheless, graphene oxide (GO) and reduced GO (rGO) are still under investigation for improving their dispersibility in aqueous solutions and their safety in different cell types. This work explores the interaction of GO and rGO with different polymeric dispersants, such as glycol chitosan (GC), propylene glycol alginate (PGA), and polydopamine (PDA), and their effects on human chondrocytes. GO was synthesized using Hummer’s method, followed by a sonication-assisted liquid-phase exfoliation (LPE) process, drying, and thermal reduction to obtain rGO. The flakes of GO and rGO exhibited an average lateral size of 8.8 ± 4.6 and 18.3 ± 8.5 µm, respectively. Their dispersibility and colloidal stability were investigated in the presence of the polymeric surfactants, resulting in an improvement in the suspension stability in terms of average size and polydispersity index over 1 h, in particular for PDA. Furthermore, cytotoxic effects induced by coated and uncoated GO and rGO on human chondrocytes at different concentrations (12.5, 25, 50 and 100 µg/mL) were assessed through LDH assay. Results showed a concentration-dependent response, and the presence of PGA contributed to statistically decreasing the difference in the LDH activity with respect to the control. These results open the way to a potentially safer use of these nanomaterials in the fields of cartilage tissue engineering and regenerative medicine.

  • Piezoelectric Nanomaterials Activated by Ultrasound: The Pathway from Discovery to Future Clinical Adoption
    Andrea Cafarelli, Attilio Marino, Lorenzo Vannozzi, Josep Puigmartí-Luis, Salvador Pané, Gianni Ciofani, and Leonardo Ricotti

    American Chemical Society (ACS)
    Electrical stimulation has shown great promise in biomedical applications, such as regenerative medicine, neuromodulation, and cancer treatment. Yet, the use of electrical end effectors such as electrodes requires connectors and batteries, which dramatically hamper the translation of electrical stimulation technologies in several scenarios. Piezoelectric nanomaterials can overcome the limitations of current electrical stimulation procedures as they can be wirelessly activated by external energy sources such as ultrasound. Wireless electrical stimulation mediated by piezoelectric nanoarchitectures constitutes an innovative paradigm enabling the induction of electrical cues within the body in a localized, wireless, and minimally invasive fashion. In this review, we highlight the fundamental mechanisms of acoustically mediated piezoelectric stimulation and its applications in the biomedical area. Yet, the adoption of this technology in a clinical practice is in its infancy, as several open issues, such as piezoelectric properties measurement, control of the ultrasound dose in vitro, modeling and measurement of the piezo effects, knowledge on the triggered bioeffects, therapy targeting, biocompatibility studies, and control of the ultrasound dose delivered in vivo, must be addressed. This article explores the current open challenges in piezoelectric stimulation and proposes strategies that may guide future research efforts in this field toward the translation of this technology to the clinical scene.

  • Correction: Graphene Oxide-Doped Gellan Gum–PEGDA Bilayered Hydrogel Mimicking the Mechanical and Lubrication Properties of Articular Cartilage (Advanced Healthcare Materials, (2021), 10, 7, (2001434), 10.1002/adhm.202001434)
    Diego Trucco, Lorenzo Vannozzi, Eti Teblum, Madina Telkhozhayeva, Gilbert Daniel Nessim, Saverio Affatato, Hind Al‐Haddad, Gina Lisignoli, and Leonardo Ricotti

    Wiley

  • Graphene Oxide-Doped Gellan Gum–PEGDA Bilayered Hydrogel Mimicking the Mechanical and Lubrication Properties of Articular Cartilage
    Diego Trucco, Lorenzo Vannozzi, Eti Teblum, Madina Telkhozhayeva, Gilbert Daniel Nessim, Saverio Affatato, Hind Al‐Haddad, Gina Lisignoli, and Leonardo Ricotti

    Wiley
    AbstractArticular cartilage (AC) is a specialized connective tissue able to provide a low‐friction gliding surface supporting shock‐absorption, reducing stresses, and guaranteeing wear‐resistance thanks to its structure and mechanical and lubrication properties. Being an avascular tissue, AC has a limited ability to heal defects. Nowadays, conventional strategies show several limitations, which results in ineffective restoration of chondral defects. Several tissue engineering approaches have been proposed to restore the AC's native properties without reproducing its mechanical and lubrication properties yet. This work reports the fabrication of a bilayered structure made of gellan gum (GG) and poly (ethylene glycol) diacrylate (PEGDA), able to mimic the mechanical and lubrication features of both AC superficial and deep zones. Through appropriate combinations of GG and PEGDA, cartilage Young's modulus is effectively mimicked for both zones. Graphene oxide is used as a dopant agent for the superficial hydrogel layer, demonstrating a lower friction than the nondoped counterpart. The bilayered hydrogel's antiwear properties are confirmed by using a knee simulator, following ISO 14243. Finally, in vitro tests with human chondrocytes confirm the absence of cytotoxicity effects. The results shown in this paper open the way to a multilayered synthetic injectable or surgically implantable filler for restoring AC defects.

  • Wear behavior characterization of hydrogels constructs for cartilage tissue replacement
    Saverio Affatato, Diego Trucco, Paola Taddei, Lorenzo Vannozzi, Leonardo Ricotti, Gilbert Nessim, and Gina Lisignoli

    MDPI AG
    This paper aims to characterize the wear behavior of hydrogel constructs designed for human articular cartilage replacement. To this purpose, poly (ethylene glycol) diacrylate (PEGDA) 10% w/v and gellan gum (GG) 1.5% w/v were used to reproduce the superior (SUP) cartilage layer and PEGDA 15% w/v and GG 1.5% w/v were used to reproduce the deep (DEEP) cartilage layer, with or without graphene oxide (GO). These materials (SUP and DEEP) were analyzed alone and in combination to mimic the zonal architecture of human articular cartilage. The developed constructs were tested using a four-station displacement control knee joint simulator under bovine calf serum. Roughness and micro-computer tomography (µ-CT) measurements evidenced that the hydrogels with 10% w/v of PEGDA showed a worse behavior both in terms of roughness increase and loss of uniformly distributed density than 15% w/v of PEGDA. The simultaneous presence of GO and 15% w/v PEGDA contributed to keeping the hydrogel construct’s characteristics. The Raman spectra of the control samples showed the presence of unreacted C=C bonds in all the hydrogels. The degree of crosslinking increased along the series SUP &lt; DEEP + SUP &lt; DEEP without GO. The Raman spectra of the tested hydrogels showed the loss of diacrylate groups in all the samples, due to the washout of unreacted PEGDA in bovine calf serum aqueous environment. The loss decreased along the series SUP &gt; DEEP + SUP &gt; DEEP, further confirming that the degree of photo-crosslinking of the starting materials plays a key role in determining their wear behavior. μ-CT and Raman spectroscopy proved to be suitable techniques to characterize the structure and composition of hydrogels.

  • Biohybrid Microrobots
    Federica Iberite, Lorenzo Vannozzi, and Leonardo Ricotti

    Springer International Publishing

  • Effects of the 3D Geometry Reconstruction on the Estimation of 3D Porous Scaffold Permeability
    Daniele Guarnera, Federica Iberite, Marco Piazzoni, Irini Gerges, Tommaso Santaniello, Lorenzo Vannozzi, Cristina Lenardi, and Leonardo Ricotti

    IEEE
    3D scaffolds for tissue engineering typically need to adopt a dynamic culture to foster cell distribution and survival throughout the scaffold. It is, therefore, crucial to know fluids' behavior inside the scaffold architecture, especially for complex porous ones. Here we report a comparison between simulated and measured permeability of a porous 3D scaffold, focusing on different modeling parameters. The scaffold features were extracted by microcomputed tomography (µCT) and representative volume elements were used for the computational fluid-dynamic analyses. The objective was to investigate the sensitivity of the model to the degree of detail of the µCT image and the elements of the mesh. These findings highlight the pros and cons of the modeling strategy adopted and the importance of such parameters in analyzing fluid behavior in 3D scaffolds.

  • A Coupled FEM-SPH Modeling Technique to Investigate the Contractility of Biohybrid Thin Films
    Lorenzo Vannozzi, Tommaso Mazzocchi, Arihiro Hasebe, Shinji Takeoka, Toshinori Fujie, and Leonardo Ricotti

    Wiley
    AbstractBiohybrid actuators have the potential to overcome the limitations of traditional actuators employed in robotics, thanks to the unique features of living contractile muscle cells, which can be used to power artificial elements. This paper describes a computational approach for the estimation of the contractile capabilities of skeletal muscle cell‐powered biohybrid actuators based on polymeric thin films. The proposed model grounds on the coupling between finite element modeling and smooth particle hydrodynamics. This allows describing the overall condition, including the viscous forces caused by the surrounding liquid medium, in which biohybrid systems are normally immersed. The model is calibrated by analyzing the contractile behavior of polydimethylsiloxane films coupled with skeletal muscle cells, reported in the literature as muscular thin films. Afterward, it is applied to poly (D, L‐lactic acid) thin films to explore the behavior of these systems, due to myotubes cultured on them, evaluating the role of thickness, tissue maturation status, and hydrostatic pressure on the contractile performance. These results pave the way toward a novel optimization approach of biohybrid robot design relying on the simulation of all the boundary conditions, thus reducing the need for extensive trial‐and‐error efforts.

  • Novel Ultrathin Films Based on a Blend of PEG- b-PCL and PLLA and Doped with ZnO Nanoparticles
    Lorenzo Vannozzi, Pedro Gouveia, Pasqualantonio Pingue, Claudio Canale, and Leonardo Ricotti

    American Chemical Society (ACS)
    In this paper a novel nanofilm type is proposed, based on a blend of poly(ethylene glycol)-block-poly(ɛ-caprolactone) methyl ether (PEG-b-PCL) and poly(L-lactic acid) (PLLA), doped with zinc oxide nanoparticles (ZnO NPs) at different concentrations (0.1, 1 and 10 mg/mL). All nanofilm types were featured by a thickness value of ~ 500 nm. Increasing ZnO NPs concentrations implied larger roughness values (~ 22 nm for the bare nanofilm, ~ 67 nm for the films with 10 mg/mL NPs), larger piezoelectricity (average d33 coefficient for the film up to ~ 1.98 pm/V) and elastic modulus: nanofilms doped with 1 and 10 mg/mL NPs resulted much stiffer than the non-doped controls and nanofilms doped with 0.1 mg/mL NPs. The ZnO NPs content was also directly proportional to the material melting point and crystallinity and inversely proportional to the material degradation rate, thus highlighting the stabilization role of zinc oxide particles. In vitro tests were carried out with cells of the musculoskeletal apparatus (fibroblasts, osteoblasts chondrocytes and myoblasts). All cell types showed good adhesion and viability on all substrate formulations. Interestingly, a higher content of ZnO NPs in the matrix demonstrated higher bioactivity, boosting the metabolic activity of fibroblasts, myoblasts and chondrocytes and enhancing the osteogenic and myogenic differentiation. These findings demonstrated the potential of these nanocomposite matrices for regenerative medicine applications, such as tissue engineering.

  • Combined Effects of Electrical Stimulation and Protein Coatings on Myotube Formation in a Soft Porous Scaffold
    Federica Iberite, Irini Gerges, Lorenzo Vannozzi, Attilio Marino, Marco Piazzoni, Tommaso Santaniello, Cristina Lenardi, and Leonardo Ricotti

    Springer Science and Business Media LLC

  • Gellan gum-based hydrogels as injectable materials for cartilage tissue engineering