Diffuse reflectance spectroscopy of the cartilage tissue in the fourth optical window.

Studies of the optical properties of biological tissues in the infrared range have demonstrated significant potential for diagnostic tasks. One of the insufficiently explored ranges for diagnostic problems at the moment is the fourth transparency window, or short wavelength infrared region II (SWIR II). A Cr2+:ZnSe laser with tuning capability in the range from 2.1 to 2.4 µm was developed to explore the possibilities in this region. The capability of diffuse reflectance spectroscopy to analyze water and collagen content in biosamples was investigated using the optical gelatin phantoms and the cartilage tissue samples during their drying process. It was demonstrated that decomposition components of the optical density spectra correlated with the partial content of the collagen and water in the samples. The present study indicates the possibility of using this spectral range for the development of diagnostic methods, in particular, for observation of the changes in the content of cartilage tissue components in degenerative diseases such as osteoarthritis.

Grading cartilage damage with diffuse reflectance spectroscopy: Optical markers and mechanical properties.

Osteoarthritis (OA) is one of the most common joint diseases worldwide. Unfortunately, clinical methods lack the ability to detect OA in the early stages. Timely detection of the knee joint degradation at the level of tissue changes can prevent its progressive damage. Here, diffuse reflectance spectroscopy (DRS) in the NIR range was used to obtain optical markers of the cartilage damage grades and to assess its mechanical properties. It was observed that the water content obtained by DRS strongly correlates with the cartilage thickness (R = .82) and viscoelastic relaxation time (R = .7). Moreover, the spectral parameters, including water content (OH-band), protein content (CH-band), and scattering parameters allowed for discrimination between the cartilage damage grades (10-4 < P ≤ 10-3 ). The developed approach may become a valuable addition to arthroscopy, helping to identify lesions at the microscopic level in the early stages of OA and complement the surgical analysis.

Autologous bone marrow-derived mesenchymal stem cells provide complete regeneration in a rabbit model of the Achilles tendon bundle rupture.

PURPOSE: To ascertain the role of autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) in the tendon regeneration. METHODS: The study was conducted on 58 Achilles tendons from 29 laboratory Chinchilla adult rabbits. The central bundles of 48 tendons were partially removed and substituted with a tissue-engineered construct consisting of a collagen sponge either loaded with BM-MSCs (n = 24) or cell free (n = 24), placed inside a Vicryl mesh tube. The ends of the resected tendon were inserted in the construct to reach a direct contact with the sponge and sutured to the tube. The animals were sacrificed three and six months post-surgery. Ten intact tendons from five rabbits were used as an untreated control. The tissue samples (n = 30) were stained with haematoxylin and eosin, Picrosirius red, primary antibodies to collagen types I and III and studied by bright-field, phase-contrast, polarized light, and scanning electron microscopies followed by semi-quantitative morphometry. RESULTS: Six months results of cell-loaded scaffolds demonstrated parallel collagen fibres, spindle-shaped tenocytes, and neoangiogenesis. In the control cell-free group, the injured areas were filled with a nonspecific fibrotic tissue with minor foci of incomplete regeneration. The biomechanical tests of 28 tendons taken from 14 rabbits showed that the stiffness of the cell-based reconstructed tendons increased to 98% of the value for the intact samples. CONCLUSION: The obtained results support the hypothesis that the application of BM-MSCs in a tissue-engineered tendon construct leads to the restitution of the tendon tissue.

Lactoferrin as a regenerative agent: The old-new panacea?

Lactoferrin (Lf) possesses various biological properties and therapeutic potentials being a perspective anti-inflammatory, antibacterial, antiviral, antioxidant, antitumor, and immunomodulatory agent. A significant body of literature has also demonstrated that Lf modulates regenerative processes in different anatomical structures, such as bone, cartilage, skin, mucosa, cornea, tendon, vasculature, and adipose tissue. Hence, this review collected and analyzed the data on the regenerative effects of Lf, as well as paid specific attention to their molecular basis. Furthermore, tissue and condition-specific activities of different Lf types as well as problems of their delivery to the targeted organs were discussed. The authors strongly hope that this review will stimulate researchers to focus on the highlighted topics thus accelerating the progress of Lf's wider clinical application.

C-reactive protein as marker of post-operative analgesic quality after primary total knee arthroplasty.

OBJECTIVE: To study the correlation between the level of C-reactive protein (CRP) and the severity of pain in the post-operative period with primary total knee arthroplasty and to conduct a comparative assessment of these indicators with various methods of pain relief. The primary hypothesis of the investigation was that post-operative CRP level is likely to be correlated with the severity of post-operative pain after total knee arthroplasty. The secondary points were the evaluation of CRP and pain syndrome in the groups, as well as the identification of the correlation between the level of CRP and the method of analgesia. MATERIALS AND METHODS: Peri-operative levels of CRP and pain syndrome (10-point visual analogue scale) studied 160 patients with grade III gonarthrosis who have underwent primary total knee arthroplasty under conditions of subarachnoid anaesthesia in the period from years 2017 to 2019. Depending on the method of post-operative analgesia, patients were divided into five groups: group 1 had only systemic multimodal analgesia (SMA, n = 56), group 2 were treated with the epidural analgesia (EDA, n = 20), group 3 had local high-volume infiltration anaesthesia (LHVIA, n = 20), group 4 were getting LHVIA with a wound catheter (LHVIAc, n = 48), and group 5 had a single blockade of the femoral nerve (FNB, n = 16). RESULTS: A direct strong correlation was obtained between the level of CRP and the severity of pain syndrome in the knee joint during movement in four to six hours after surgery (n = 160, Kendall coefficient τ = 0.230, p = 0,000) and on the first post-operative day (n = 160, τ = 0.21, p = 0.001). The increase in CRP (the difference between pre-operative and post-operative CRP levels) also was positively correlated with the severity of pain in the post-operative period (n = 160, τ = 0.257, p = 0.000 and τ = 0.187, p = 0.001, respectively). CRP level significantly has increased in the post-operative period (p = 0,000). The lowest CRP indicators in the first post-operative day were recorded during the infiltrative anaesthesia (3rd and 4th groups);, the highest were during the administration of SMA group (1st group). CONCLUSION: The results confirm the correlation between the level of CRP and the severity of pain syndrome in the early post-operative period after total knee arthroplasty, its dependence on the method of analgesia, and allow to use it as a criterion for evaluating of the effectiveness of analgesia.