An in vitro model for osteoarthritis using long-cultured inflammatory human macrophages repeatedly stimulated with TLR agonists.

Osteoarthritis (OA) is characterized by an abundance of inflammatory M1-like macrophages damaging local tissues. The search for new potential drugs for OA suffers from the lack of appropriate methods of long-lasting inflammation. Here we developed and characterized an in vitro protocol of long-lasting culture of primary human monocyte-derived macrophages differentiated with a combination of M-CSF+GM-CSF that optimally supported long-cultured macrophages (LC-Mϕs) for up to 15 days, unlike their single use. Macrophages repeatedly stimulated for 15 days with the TLR2 ligand Pam3CSK4 (LCS-Mϕs), showed sustained levels over time of IL-6, CCL2, and CXCL8, inflammatory mediators that were also detected in the synovial fluids of OA patients. Furthermore, macrophages isolated from the synovia of two OA patients showed an expression profile of inflammation-related genes similar to that of LCS-Mϕs, validating our protocol as a model of chronically activated inflammatory macrophages. Next, to confirm that these LCS-Mϕs could be modulated by anti-inflammatory compounds, we employed dexamethasone and/or celecoxib, two drugs widely used in OA treatment, that significantly inhibited the production of inflammatory mediators. This easy-to-use in vitro protocol of long-lasting inflammation with primary human macrophages could be useful for the screening of new compounds to improve the therapy of inflammatory disorders.

The Role of Bifidobacteria in Predictive and Preventive Medicine: A Focus on Eczema and Hypercholesterolemia.

Bifidobacteria colonize the human gastrointestinal tract early on in life, their interaction with the host starting soon after birth. The health benefits are strain specific and could be due to the produced polysaccharides. The consumption of probiotics may prevent obesity, irritable bowel syndrome, eczema or atopic dermatitis, and asthma. Non-replicative strains of Bifidobacterium longum (NCC3001 and NCC2705) promote the differentiation of normal human epidermal keratinocytes (NHEKs), inducing a high expression of differentiation markers (keratin -KRT1-, and transglutaminase -TGM1-) and pro-regeneration markers (cathepsins), including ß-defensin-1, which plays an important role in modulating the cutaneous immune response. Strains belonging to the genera Bifidobacterium and Lactobacillus can increase tight-junction proteins in NHEKs and enhance barrier function. Bifidobacteria and lactobacilli may be used as prophylactic or therapeutic agents towards enteric pathogens, antibiotic-associated diarrhea, lactose intolerance, ulcerative colitis, irritable bowel syndrome, colorectal cancer, cholesterol reduction, and control of obesity and metabolic disorders. Bifidobacterium bifidum showed an in vitro capability of lowering cholesterol levels thanks to its absorption into the bacterial membrane. Several strains of the species Lactobacillus acidophilus, L. delbrueckii subsp. bulgaricus, L. casei, and L. gasseri led to a reduced amount of serum cholesterol due to their ability to assimilate cholesterol (in vitro). Lactococcus lactis KF147 and Lactobacillus plantarum Lp81 have also been shown to reduce cholesterol levels by 12%. Clarifying the specific health mechanisms of Bifidobacterium and Lactobacillus strains in preventing high-cost pathologies could be useful for delineating effective guidelines for the treatment of infants and adults.

Hyaluronic Acid as a Protein Polymeric Carrier: An Overview and a Report on Human Growth Hormone.

Hyaluronic acid (HA) is a natural polysaccharide primarily present in the vitreous humor and in cartilages where it plays a key structural role in organizing the cartilage extracellular matrix. HA is used in a wide range of applications including treatment of arthritis (as a viscosupplementation agent for joints) and in a variety of cosmetic injectable products. Its safety profile is thus well established. Thanks to its high biocompatibility and targeting properties, HA has also been investigated for use as a carrier of anticancer drugs and, recently, also of proteins. Its role in the last case is a particularly challenging one as dedicated coupling chemistries are required to preserve the protein's conformation and activity. This study focuses on the state of the art on protein HAylation. New data from our laboratory on the local delivery of specific biologics to joints will also be outlined.

Wave simulation in biologic media based on the Kelvin-Voigt fractional-derivative stress-strain relation.

The acoustic behavior of biologic media can be described more realistically using a stress-strain relation based on fractional time derivatives of the strain, since the fractional exponent is an additional fitting parameter. We consider a generalization of the Kelvin-Voigt rheology to the case of rational orders of differentiation, the so-called Kelvin-Voigt fractional-derivative (KVFD) constitutive equation, and introduce a novel modeling method to solve the wave equation by means of the Grünwald-Letnikov approximation and the staggered Fourier pseudospectral method to compute the spatial derivatives. The algorithm can handle complex geometries and general material-property variability. We verify the results by comparison with the analytical solution obtained for wave propagation in homogeneous media. Moreover, we illustrate the use of the algorithm by simulation of wave propagation in normal and cancerous breast tissue.