Maurizio Lannocca

An innovative stand-alone bioreactor for the highly reproducible transfer of cyclic mechanical stretch to stem cells cultured in a 3D scaffold

Much evidence in the literature demonstrates the effect of cyclic mechanical stretch in maintaining, or addressing, a muscle phenotype. Such results were obtained using several technical approaches, useful for the experimental collection of proofs of principle but probably unsuitable for application in clinical regenerative medicine. Here we aimed to design a reliable innovative bioreactor, acting as a stand‐alone cell culture incubator, easy to operate and effective in addressing mesenchymal stem cells (MSCs) seeded onto a 3D bioreabsorbable scaffold, towards a muscle phenotype via the transfer of a controlled and highly‐reproducible cyclic deformation. Electron microscopy, immunohistochemistry and biochemical analysis of the obtained pseudotissue constructs showed that cells ‘trained’ over 1 week: (a) displayed multilayer organization and invaded the 3D mesh of the scaffold; and (b) expressed typical markers of muscle cells. This effect was due only to physical stimulation of the cells, without the need of any other chemical or genetic manipulation. This device is thus proposed as a prototypal instrument to obtain pseudotissue constructs to test in cardiovascular regenerative medicine, using good manufacturing procedures. Copyright

Comparison of Knee Cruciate Ligaments Models Using Kinematics from a Living Subject during Chair Rising-Sitting

The knee joint is a key structure of the human locomotor system. Any lesion or pathology compromising its mobility and stability alters its function. As direct measurements of the contribution of each anatomical structure to the joint function are not viable, modelling techniques must be applied. The present study is aimed at comparing cruciate ligaments models of different complexity using accurate parameters from RMN and 3D-fluoroscopy of a single selected subject during chair rising-sitting motor task.. The complexity of the model was not relevant for the calculation of the strain range of the cruciate ligaments fibres. On the other hand, three-dimensionality and anatomical twist of the modelled fibres resulted to be fundamental for the geometrical strain distribution over the ligament section.

Estimation of knee ligaments loads using the modelling approach applied on in-vivo accurate kinematics and morphology of a young subject

The knee joint is a key structure of the human locomotor system. Any lesion or pathology compromising its mobility and stability alters its function. As direct measurements of the contribution of each anatomical structure to the joint function are not viable, modelling techniques must be applied. The present study is aimed at evaluating the importance of anatomical twist in the determination of mechanical stabilising action of the cruciate ligaments during the execution of a daily living activity. For this purpose accurate parameters from nuclear magnetic resonance and 3D-fluoroscopy of a single selected subject during chair risingsitting motor task were used. The modelling of the twist of fibres was fundamental in the determination of the specific behaviour of the posterior cruciate ligament in particular.

Transcallosal Inhibition during Motor Imagery: Analysis of a Neural Mass Model

The EEG rhythmic activities of the somato-sensory cortex reveal event-related desynchronization (ERD) or event-related synchronization (ERS) in beta band (14–30 Hz) as subjects perform certain tasks or react to specific stimuli. Data reported for imagination of movement support the hypothesis that activation of one sensorimotor area (SMA) can be accompanied by deactivation of the other. In order to improve our understanding of beta ERD/ERS generation, two neural mass models (NMM) of a cortical column taken from Wendling et al. (2002) were interconnected to simulate the transmission of information from one cortex to the other. The results show that the excitation of one cortex leads to inhibition of the other and vice versa, enforcing the Theory of Inhibition. This behavior strongly depends on the initial working point (WP) of the neural populations (between the linear and the upper saturation region of a sigmoidal function) and on how the cortical activation or deactivation can move the WP in the upper saturation region ERD or in the linear region ERS, respectively.

A Device to Test the Primary Stability in Cementless Hip Arthroplasty Through Mechanical Vibrations

Primary stability of cementless prostheses is critical for the long term outcome of the operation. Cementless implants are mechanically stabilized during surgery through a press-fitting procedure. To achieve a good initial stability, it is important that the surgeon performs an optimal press-fitting, avoiding both problems of stem loosening, and micro-cracking of the host bone. A possible approach to solve this problem and assist the surgeon in achieving the optimal compromise, involves the use of the vibration analysis. This technique was used in the presented study, which was aimed to design and test a prototype device able to evaluate the primary stability of a cementless prosthesis, at the femoral level. In particular, the goal was to discriminate between stable and quasi-stable implants; thus the stem-bone system was assumed linear in both cases. For that reason, it was decided to study the frequency responses of the system, instead of the harmonic distortion. The prototype was developed. It is mainly composed by a piezoelectric exciter connected to the stem and an accelerometer attached to the femur. Preliminary tests were performed on a composite femur implanted with a conventional stem. The results showed that the input signal is repeatable and the output can be accurately recorded. The parameters that seem to be more sensitive to stability are the resonance frequency and the amplitude at the resonance frequency.Copyright

Comparison of Knee Cruciate Ligaments Models Using In-vivo Step Up-Down Kinematics

The knee joint is a key structure of the human locomotor system. Any lesion or pathology compromising its mobility and stability alters its function. As direct measurements of the contribution of each anatomical structure to the joint function are not viable, modelling techniques must be applied. The present study is aimed at comparing cruciate ligaments models of different complexity using accurate parameters from MRI and 3D-fluoroscopy of a single selected subject during step up-down motor task. The complexity of the model was not very relevant for the calculation of the strain range of the cruciate ligaments fibres. On the other hand, three-dimensionality and anatomical twist of the modelled fibres resulted to be fundamental for the geometrical strain distribution over the ligament section.