Designing Antitrypanosomal and Antileishmanial BODIPY Derivatives: A Computational and In Vitro Assessment.

Leishmaniasis and Human African trypanosomiasis pose significant public health threats in resource-limited regions, accentuated by the drawbacks of the current antiprotozoal treatments and the lack of approved vaccines. Considering the demand for novel therapeutic drugs, a series of BODIPY derivatives with several functionalizations at the meso, 2 and/or 6 positions of the core were synthesized and characterized. The in vitro activity against Trypanosoma brucei and Leishmania major parasites was carried out alongside a human healthy cell line (MRC-5) to establish selectivity indices (SIs). Notably, the meso-substituted BODIPY, with 1-dimethylaminonaphthalene (1b) and anthracene moiety (1c), were the most active against L. major, displaying IC50 = 4.84 and 5.41 µM, with a 16 and 18-fold selectivity over MRC-5 cells, respectively. In contrast, the mono-formylated analogues 2b and 2c exhibited the highest toxicity (IC50 = 2.84 and 6.17 µM, respectively) and selectivity (SI = 24 and 11, respectively) against T. brucei. Further insights on the activity of these compounds were gathered from molecular docking studies. The results suggest that these BODIPYs act as competitive inhibitors targeting the NADPH/NADP+ linkage site of the pteridine reductase (PR) enzyme. Additionally, these findings unveil a range of quasi-degenerate binding complexes formed between the PRs and the investigated BODIPY derivatives. These results suggest a potential correlation between the anti-parasitic activity and the presence of multiple configurations that block the same site of the enzyme.

Spleen stiffness: a new tool to predict high-risk varices in cirrhotic patients.

INTRODUCTION: Cirrhosis is one of the major causes of morbidity and mortality worldwide. Portal hypertension is the major contributor of cirrhosis-related complications and is defined as a hepatic venous pressure gradient (HVPG) > 5 mmHg. Measurement of HVPG is an invasive, difficult, and costly procedure. Therefore, it is only performed in specialized centers. Liver stiffness measured with transient elastography is one of the most studied noninvasive markers of portal hypertension, and spleen elastography has recently emerged as an important adjuvant tool. The development of a new probe (100 Hz) that more reliably reflect the grade of portal hypertension evaluated by spleen stiffness measurement has improved the accuracy of this technique. The aim of this work was to evaluate the accuracy of spleen stiffness with the new dedicated probe to predict the presence of high-risk varices, as well as to determine the ideal cutoff to predict it. METHODS: Prospective study of cirrhotic patients admitted to upper endoscopy that were also submitted to liver and spleen elastography with the 100-Hz probe by the same blinded operator in a tertiary center. RESULTS: We included 209 cirrhotic patients, with mean age of 61.9 years (±9.9), 77.0% male. The most common etiology was alcoholic liver disease (72.7%). The median value of liver elastography was 25.3 [4.5-75] kPa, and the median value of spleen elastography was 42.4 [7.6-100] kPa. At the cutoff of 53.25 kPa, we obtained sensitivity of 100% and specificity of 72.6% to predict high-risk varices, and, according to this cutoff, 133/175 of esophagogastroduodenoscopy could have been spared (76.0%), while according to Baveno guidelines, only 51/175 would have been spared (29.1%). CONCLUSION: In the era of noninvasive exams, spleen elastography with the 100-Hz probe emerges as an excellent tool for prediction of presence of high-risk varices. At the cutoff of 53.25 kPa, spleen elastography avoids upper endoscopy for screening for high-risk varices, promising to be become part of the hepatologists' daily routine.

Colorimetric Chemosensor for Cu2+ and Fe3+ Based on a meso-Triphenylamine-BODIPY Derivative.

Optical chemosensors are a practical tool for the detection and quantification of important analytes in biological and environmental fields, such as Cu2+ and Fe3+. To the best of our knowledge, a BODIPY derivative capable of detecting Cu2+ and Fe3+ simultaneously through a colorimetric response has not yet been described in the literature. In this work, a meso-triphenylamine-BODIPY derivative is reported for the highly selective detection of Cu2+ and Fe3+. In the preliminary chemosensing study, this compound showed a significant color change from yellow to blue-green in the presence of Cu2+ and Fe3+. With only one equivalent of cation, a change in the absorption band of the compound and the appearance of a new band around 700 nm were observed. Furthermore, only 10 equivalents of Cu2+/Fe3+ were needed to reach the absorption plateau in the UV-visible titrations. Compound 1 showed excellent sensitivity toward Cu2+ and Fe3+ detection, with LODs of 0.63 µM and 1.06 µM, respectively. The binding constant calculation indicated a strong complexation between compound 1 and Cu2+/Fe3+ ions. The 1H and 19F NMR titrations showed that an increasing concentration of cations induced a broadening and shifting of the aromatic region peaks, as well as the disappearance of the original fluorine peaks of the BODIPY core, which suggests that the ligand-metal (1:2) interaction may occur through the triphenylamino group and the BODIPY core.

Polyaromatic Bis(indolyl)methane Derivatives with Antiproliferative and Antiparasitic Activity.

Bis(indolyl)methanes (BIMs) are a class of compounds that have been recognized as an important core in the design of drugs with important pharmacological properties, such as promising anticancer and antiparasitic activities. Here, we explored the biological activity of the BIM core functionalized with different (hetero)aromatic moieties. We synthesized substituted BIM derivatives with triphenylamine, N,N-dimethyl-1-naphthylamine and 8-hydroxylquinolyl groups, studied their photophysical properties and evaluated their in vitro antiproliferative and antiparasitic activities. The triphenylamine BIM derivative 2a displayed an IC50 of 3.21, 3.30 and 3.93 µM against Trypanosoma brucei, Leishmania major and HT-29 cancer cell line, respectively. The selectivity index demonstrated that compound 2a was up to eight-fold more active against the parasites and HT-29 than against the healthy cell line MRC-5. Fluorescence microscopy studies with MRC-5 cells and T. brucei parasites incubated with derivative 2a indicate that the compound seems to accumulate in the cell's mitochondria and in the parasite's nucleus. In conclusion, the BIM scaffold functionalized with the triphenylamine moiety proved to be the most promising antiparasitic and anticancer agent of this series.

Enhancement of hMSC In Vitro Proliferation by Surface Immobilization of a Heparin-Binding Peptide.

The use of human Mesenchymal Stem Cells (hMSC) as therapeutic agents for advanced clinical therapies relies on their in vitro expansion. Over the last years, several efforts have been made to optimize hMSC culture protocols, namely by mimicking the cell physiological microenvironment, which strongly relies on signals provided by the extracellular matrix (ECM). ECM glycosaminoglycans, such as heparan-sulfate, sequester adhesive proteins and soluble growth factors at the cell membrane, orchestrating signaling pathways that control cell proliferation. Surfaces exposing the synthetic polypeptide poly(L-lysine, L-leucine) (pKL) have previously been shown to bind heparin from human plasma in a selective and concentration-dependent manner. To evaluate its effect on hMSC expansion, pKL was immobilized onto self-assembled monolayers (SAMs). The pKL-SAMs were able to bind heparin, fibronectin and other serum proteins, as demonstrated by quartz crystal microbalance with dissipation (QCM-D) studies. hMSC adhesion and proliferation were significantly increased in pKL-SAMs compared to controls, most probably related to increased heparin and fibronectin binding to pKL surfaces. This proof-of-concept study highlights the potential of pKL surfaces to improve hMSC in vitro expansion possible through selective heparin/serum protein binding at the cell-material interface.

Artificial intelligence and capsule endoscopy: automatic detection of enteric protruding lesions using a convolutional neural network.

BACKGROUND AND AIMS: capsule endoscopy (CE) revolutionized the study of the small intestine. Nevertheless, reviewing CE images is time-consuming and prone to error. Artificial intelligence algorithms, particularly convolutional neural networks (CNN), are expected to overcome these drawbacks. Protruding lesions of the small intestine exhibit enormous morphological diversity in CE images. This study aimed to develop a CNN-based algorithm for the automatic detection small bowel protruding lesions. METHODS: a CNN was developed using a pool of CE images containing protruding lesions or normal mucosa from 1,229 patients. A training dataset was used for the development of the model. The performance of the network was evaluated using an independent dataset, by calculating its sensitivity, specificity, accuracy, positive and negative predictive values. RESULTS: a total of 18,625 CE images (2,830 showing protruding lesions and 15,795 normal mucosa) were included. Training and validation datasets were built with an 80 %/20 % distribution, respectively. After optimizing the architecture of the network, our model automatically detected small-bowel protruding lesions with an accuracy of 92.5 %. CNN had a sensitivity and specificity of 96.8 % and 96.5 %, respectively. The CNN analyzed the validation dataset in 53 seconds, at a rate of approximately 70 frames per second. CONCLUSIONS: we developed an accurate CNN for the automatic detection of enteric protruding lesions with a wide range of morphologies. The development of these tools may enhance the diagnostic efficiency of CE.

GLP-1: 10-year follow-up after Roux-en-Y gastric bypass.

PURPOSE: Glucagon-like peptide-1 (GLP-1) is a hormone widely studied in the short-term postoperative follow-up of Roux-en-Y gastric bypass due to its elevation and association with improvement of the glucose metabolism, but there are few studies in 10 years after RYGB follow-up with the same patient. METHODS: Twenty morbidity obesity patients were submitted to RYGB; these patients were divided into two groups: normal glucose-tolerant morbidly obese patients (NGT) 11 patients and abnormal glucose metabolism morbidly obese patients (AGM) 9 patients. Oral glucose tolerance test (OGTT) was done during four different periods: T1 (first evaluation), T2 (pre-surgery), T3 (9 months after surgery) and T4 (10 years after surgery). RESULTS: Groups were matched for age and gender, and as NGT and AGM had BMI of 46.31 ± 5.03 kg/m2 and 50.87 ± 10.31 kg/m2. After 10 years of RYGB, they were obesity grade I with BMI for NGT 32.45 ± 4.99 kg/m2 and AGM 34.85 ± 4.46 kg/m2. Plasma glucose levels decreased NGT group at T4 period had a significant reduction at 120 min after OGTT for NGT 55.49 ± 17.15 mg/dL (p˂0.001). Insulin levels changed from T1 to T4 for the NGT group. GLP-1 curves were statistically different between the NGT and AGM groups. The AGM group had a higher mean for GLP-1 secretion at T4 period and at 30 min of OGTT 63.85 ± 37.98 pmol/L when compared to NGT 50.73 ± 24.82 pmol/L with AGM > NGT with p˂0.001. CONCLUSION: Evaluation of the same patient during 4 different periods shows that, even with weight regain, after 10-years of RYGB high levels of GLP-1 remained which can be associated with metabolic improvement especially at the NGT group.

Characterization and Genomic Analysis of a New Phage Infecting Helicobacter pylori.

Helicobacter pylori, a significant human gastric pathogen, has been demonstrating increased antibiotic resistance, causing difficulties in infection treatment. It is therefore important to develop alternatives or complementary approaches to antibiotics to tackle H. pylori infections, and (bacterio)phages have proven to be effective antibacterial agents. In this work, prophage isolation was attempted using H. pylori strains and UV radiation. One phage was isolated and further characterized to assess potential phage-inspired therapeutic alternatives to H. pylori infections. HPy1R is a new podovirus prophage with a genome length of 31,162 bp, 37.1% GC, encoding 36 predicted proteins, of which 17 were identified as structural. Phage particles remained stable at 37 °C, from pH 3 to 11, for 24 h in standard assays. Moreover, when submitted to an in vitro gastric digestion model, only a small decrease was observed in the gastric phase, suggesting that it is adapted to the gastric tract environment. Together with its other characteristics, its capability to suppress H. pylori population levels for up to 24 h post-infection at multiplicities of infection of 0.01, 0.1, and 1 suggests that this newly isolated phage is a potential candidate for phage therapy in the absence of strictly lytic phages.

Bioimaging of Lysosomes with a BODIPY pH-Dependent Fluorescent Probe.

Fluorescence-based probes represent a powerful tool for noninvasive imaging of living systems in real time and with a high temporal and spatial resolution. Amongst several known fluorophores, 3-difluoroborodipyrromethene (BODIPY) derivatives have become a cornerstone for innovative fluorescent labelling applications, mainly due to their advantageous features including their facile synthesis, structural versatility and exceptional photophysical properties. In this context, we report a BODIPY-based fluorescent probe for imaging of lysosomes in living cells. The BODIPY derivative displayed a remarkable fluorescence enhancement at low pH values with a pKa* of 3.1. In vitro studies by confocal microscopy in HeLa cells demonstrated that the compound was able to permeate cell membrane and selectively label lysosome whilst remaining innocuous to the cell culture at the maximum concentration tested. Herein, the BODIPY derivative holds the promise of investigating lysosomal dynamics and function in living cells through fluorescence imaging.

Pyoderma gangrenosum in ulcerative colitis - An exuberant and painful complication.

A 41-years-old female, with ulcerative colitis, presented to the emergency department with 7-days history of abdominal pain, bloody stools (> 10/day). The patient referred the appearance of a cutaneous lesion, on her left thigh, with subsequent appearance of similar lesions on the lower limbs. No improvement after amoxicillin/clavulanic acid. On admission, she was febrile (38.2 ºC) and tachycardic. She had three cutaneous lesions, the largest one with 8cm in the left thigh - a deep and painful lesion, with extensive ulceration, necrosis, exudative edges and with marked pathergia, compatible with pyoderma gangrenosum.

Cecal MALT lymphoma: a challenging diagnosis.

A 76-year-old female with a medical history of diabetes, arterial hypertension and dyslipidemia sought medical assistance due to left flank abdominal pain, fatigue and anorexia over the previous month. Laboratory analyses were normal and the computed tomography (CT) scan showed colonic diverticulosis and mesenteric panniculitis.

Evaluation of online content of proctological disorders in the Portuguese language.

INTRODUCTION: health literacy has an increasing relevance as the disseminated access to online contents may impact on community health. This study aimed to evaluate the suitability of the online content of benign proctological disorders. METHODS: the platforms Google© and YouTube™ were searched using the keywords hemorrhoidal disease, anal fistula, anal fissure, anal pruritus and fecal incontinence. Each page was analyzed for: interactivity, credibility, readability and content adequacy. For each video, the content, reactions and comments of the users were analyzed. Three validated scales were applied: Simple Measure of Gobbledygook (SMOG); Suitability Assessment of Materials (SAM), and quality criteria for consumer health information on treatment choices (DISCERN). RESULTS: a total of 127 webpages and 113 videos were evaluated. Forty webpages (31.50 %) included images and ten (37.04 %) had informative videos. The SMOG scale had an average value of 9.91 ± 0.94, which estimates the need for ten years of schooling for comprehension and 64 webpages (52.07 %) presented a reading level higher than the recommended B1. The mean SAM score was 39.46 ± 11.2 % and the DISCERN scale averaged 40.33 ± 5.69, corresponding to a reasonable content. Only 20 pages (15.75 %) included interactivity tools and 44 (34.64 %) contained bibliographic references. The videos posted by patients (n = 67, 59.2 %) had the highest number of views and positive comments whereas videos from health professionals (n = 21; 18.75 %) had the highest proportion of requests for additional information. DISCUSSION: online content regarding benign proctological disorders is globally inappropriate for the health literacy level of the Portuguese population, both at the written and reading levels.

Hidden wounds of violence: Abnormal motor oscillatory brain activity is related to posttraumatic stress symptoms.

Victims of urban violence are at risk of developing Posttraumatic Stress Disorder (PTSD), one of the most debilitating consequences of violence. Considering that PTSD may be associated with inefficient selection of defensive responses, it is important to understand the relation between motor processing and PTSD. The present study aims to investigate the extent to which the severity of posttraumatic stress symptoms (PTSS) is related to motor preparation against visual threat cues in victims of urban violence. Participants performed a choice reaction time task while ignoring a picture that could be threating or neutral. The EEG indices extracted were the motor-related amplitude asymmetry (MRAA) in the alpha frequency range, and the lateralized readiness potential (LRP). We observed a linear relation between longer LRP latency and a slower reaction time, selectively during threat processing (compared to neutral) in low PTSS, but not in high PTSS participants. Alpha MRAA suppression and the PTSS were also linearly related: the smaller the alpha MRAA suppression in the threat condition relative to neutral, the greater the PTSS. These results provide evidence that threatening cues affect motor processing that is modulated by the severity of PTSS in victims of urban violence.

Improving houses in the Bolivian Chaco increases effectiveness of residual insecticide spraying against infestation with Triatoma infestans, vector of Chagas disease.

OBJECTIVE: Failure to control domestic Triatoma infestans in the Chaco is attributed to vulnerable adobe construction, which provides vector refuges and diminishes insecticide contact. We conducted a pilot to test the impact of housing improvement plus indoor residual spraying (IRS) on house infestation and vector abundance in a rural community in the Bolivian Chaco. METHODS: The intervention included three arms: housing improvement + IRS [HI], assisted IRS [AS] in which the team helped to clear the house pre-IRS and routine IRS [RS]. HI used locally available materials, traditional construction techniques and community participation. Vector parameters were assessed by Timed Manual Capture for 2 person-hours per house at baseline and medians of 114, 173, 314, 389 and 445 days post-IRS-1. A second IRS round was applied at a median of 314 days post-IRS-1. RESULTS: Post-intervention infestation indices and abundance fell in all three arms. The mean odds of infestation was 0.29 (95% CL 0.124, 0.684) in the HI relative to the RS arm. No difference was observed between AS and RS. Vector abundance was reduced by a mean 44% (24.8, 58.0) in HI compared to RS, with no difference between AS and RS. Median delivered insecticide concentrations per house were lower than the target of 50 mg/m2 in >90% of houses in all arms. CONCLUSION: Housing improvement using local materials and community participation is a promising strategy to improve IRS effectiveness in the Bolivian Chaco. A larger trial is needed to quantify the impact on reinfestation over time.

Sleep Disturbance in Inflammatory Bowel Disease Is Associated with Disease Activity and Adverse Outcome.

BACKGROUND: There is growing evidence about the relationship between sleep quality (SQ) and disease activity in inflammatory bowel disease (IBD). This study aimed to identify the prevalence of sleep disturbance in IBD and its predictive factors and to assess its association with worse outcome. METHODS: IBD patients were prospectively enrolled. Clinical activity, inflammatory activity (high C-reactive protein or fecal calprotectin), and SQ (assessed using the Pittsburgh Sleep Quality Index) were evaluated, and logistic regression was used to identify predictors of poor SQ at baseline. The development of disability or disease progression at 6 months (surgery, hospitalization, development of stenosis, penetrating or perianal disease, steroid dependency, or start/change immunosuppression) was compared between patients with and without poor SQ. RESULTS: Two hundred and five patients were enrolled, with 44.9% (n = 92) reporting poor SQ. On multivariate analysis, current smoking (OR 2.80), extraintestinal manifestations (OR 2.68), clinical activity (OR 3.31), and inflammatory activity (OR 4.62) were predictive factors of poor SQ. Cox proportional hazards model showed that poor SQ was predictive of worse prognosis at 6 months (HR 2.470). CONCLUSION: There is a high prevalence of poor SQ in IBD patients, highlighting the importance of its inclusion in patient-reported outcomes. Sleep disturbance seems to have prognostic value in IBD.

The invisible scars of emotional abuse: a common and highly harmful form of childhood maltreatment.

BACKGROUND: Childhood maltreatment (CM) is unfortunately widespread globally and has been linked with an increased risk of a variety of psychiatric disorders in adults, including posttraumatic stress disorder (PTSD). These associations are well established in the literature for some maltreatment forms, such as sexual and physical abuse. However, the effects of emotional maltreatment are much less explored, even though this type figures among the most common forms of childhood maltreatment. Thus, the present study aims to investigate the impact of each type of childhood maltreatment, both individually and conjointly, on revictimization and PTSD symptom severity using a nonclinical college student sample. METHODS: Five hundred and two graduate and undergraduate students participated in the study by completing questionnaires assessing lifetime traumatic experiences in general, maltreatment during childhood and PTSD symptoms. Bivariate and multivariate negative binomial regressions were applied to examine the associations among childhood maltreatment, revictimization, and PTSD symptom severity. RESULTS: Our results showed that using bivariate models, all types of CM were significantly associated with revictimization and PTSD symptom severity. Multivariate models showed that emotional abuse was the type of maltreatment associated with the highest incidence rates of revictimization and PTSD symptom severity. CONCLUSIONS: These data provide additional evidence of the harmful effects of childhood maltreatment and its long-term consequences for individuals' mental health. Notably, the findings highlight the importance of studying the impacts of emotional abuse, which seems to be a highly prevalent, understudied, and chronic form of maltreatment that is as toxic as other maltreatment forms.

Terminal complement complex formation is associated with intervertebral disc degeneration.

PURPOSE: The complement system is a crucial part of innate immunity. Recent work demonstrated an unexpected contribution to tissue homeostasis and degeneration. This study investigated for the first time, in human disc tissues, the deposition profile of the complement activation product terminal complement complex (TCC), an inflammatory trigger and inducer of cell lysis, and its inhibitor CD59, and their correlation with the degree of disc degeneration (DD). METHODS: Disc biopsies were collected from patients diagnosed with DD (n = 39, age 63 ± 12) and adolescent idiopathic scoliosis (AIS, n = 10, age 17 ± 4) and compared with discs from healthy Young (n = 11, age 7 ± 7) and Elder (n = 10, age 65 ± 15) donors. Immunohistochemical detection of TCC and CD59 in nucleus pulposus (NP), annulus fibrosus (AF) and endplate (EP) was correlated with age, Pfirrmann grade and Modic changes. RESULTS: Higher percentage of TCC+ cells was detected in the NP and EP of DD compared to Elder (P < 0.05), and in the EP of Young versus Elder (P < 0.001). In DD, TCC deposition was positively correlated with Pfirrmann grade, but not with Modic changes, whereas for Young donors, a negative correlation was found with age, indicating TCC's involvement not only in DD, but also in early stages of skeletal development. Higher CD59 positivity was found in AIS and DD groups compared to Young (P < 0.05), and it was negatively correlated with the age of the patients. CONCLUSION: TCC deposition positively correlated with the degree of disc degeneration. A functional relevance of TCC may exist in DD, representing a potential target for new therapeutics.

Interleukin-1ß and cathepsin D modulate formation of the terminal complement complex in cultured human disc tissue.

PURPOSE: Formation of terminal complement complex (TCC), a downstream complement system activation product inducing inflammatory processes and cell lysis, has been identified in degenerated discs. However, it remains unclear which molecular factors regulate complement activation during disc degeneration (DD). This study investigated a possible involvement of the pro-inflammatory cytokine interleukin-1ß (IL-1ß) and the lysosomal protease cathepsin D (CTSD). METHODS: Disc biopsies were collected from patients suffering from DD (n = 43) and adolescent idiopathic scoliosis (AIS, n = 13). Standardized tissue punches and isolated cells from nucleus pulposus (NP), annulus fibrosus (AF) and endplate (EP) were stimulated with 5% human serum (HS) alone or in combination with IL-1ß, CTSD or zymosan. TCC formation and modulation by the complement regulatory proteins CD46, CD55 and CD59 were analysed. RESULTS: In DD tissue cultures, IL-1ß stimulation decreased the percentage of TCC + cells in AF and EP (P < 0.05), whereas CTSD stimulation significantly increased TCC deposition in NP (P < 0.01) and zymosan in EP (P < 0.05). Overall, the expression of CD46, CD55 and CD59 significantly increased in all isolated cells during culture (P < 0.05). Moreover, cellular TCC deposition was HS concentration dependent but unaffected by IL-1ß, CTSD or zymosan. CONCLUSION: These results suggest a functional relevance of IL-1ß and CTSD in modulating TCC formation in DD, with differences between tissue regions. Although strong TCC deposition may represent a degeneration-associated event, IL-1ß may inhibit it. In contrast, TCC formation was shown to be triggered by CTSD, indicating a multifunctional involvement in disc pathophysiology.

Therapeutic Strategies for IVD Regeneration through Hyaluronan/SDF-1-Based Hydrogel and Intravenous Administration of MSCs.

Intervertebral disc (IVD) degeneration involves a complex cascade of events, including degradation of the native extracellular matrix, loss of water content, and decreased cell numbers. Cell recruitment strategies for the IVD have been increasingly explored, aiming to recruit either endogenous or transplanted cells. This study evaluates the IVD therapeutic potential of a chemoattractant delivery system (HAPSDF5) that combines a hyaluronan-based thermoreversible hydrogel (HAP) and the chemokine stromal cell derived factor-1 (SDF-1). HAPSDF5 was injected into the IVD and was combined with an intravenous injection of mesenchymal stem/stromal cells (MSCs) in a pre-clinical in vivo IVD lesion model. The local and systemic effects were evaluated two weeks after treatment. The hydrogel by itself (HAP) did not elicit any adverse effect, showing potential to be administrated by intradiscal injection. HAPSDF5 induced higher cell numbers, but no evidence of IVD regeneration was observed. MSCs systemic injection seemed to exert a role in IVD regeneration to some extent through a paracrine effect, but no synergies were observed when HAPSDF5 was combined with MSCs. Overall, this study shows that although the injection of chemoattractant hydrogels and MSC recruitment are feasible approaches for IVD, IVD regeneration using this strategy needs to be further explored before successful clinical translation.

Modulation of the In Vivo Inflammatory Response by Pro- Versus Anti-Inflammatory Intervertebral Disc Treatments.

Inflammation is central in intervertebral disc (IVD) degeneration/regeneration mechanisms, and its balance is crucial to maintain tissue homeostasis. This work investigates the modulation of local and systemic inflammatory response associated with IVD degeneration/herniation by administration of PRO- versus ANTI-inflammatory treatments. Chitosan/poly-γ-glutamic acid nanocomplexes, known as pro-inflammatory (PRO), and soluble diclofenac, a non-steroidal anti-inflammatory drug (ANTI), were intradiscally administered in a rat IVD injury model, 24 h after lesion. Two weeks after administration, a reduction of disc height accompanied by hernia formation was observed. In the PRO-inflammatory treated group, IL-1ß, IL-6 and COX-2 IVD gene expression were upregulated, and loss of nucleus pulposus (NP) structure and composition was observed. Systemically, lower T-cell frequency was observed in the lymph nodes (LN) and spleen (SP) of the PRO group, together with an increase in CD4+ T cells subset in the blood (BL) and LN. In contrast, the ANTI-group had higher proteoglycans/collagen ratio and collagen type 2 content in the NP, while an increase in the frequency of myeloid cells, M1 macrophages and activated macrophages (MHCII+) was observed at the systemic level. Overall, this study illustrates the dynamics of local and systemic inflammatory and immune cell responses associated with intradiscal therapies, which will contribute to designing more successful immunomodulatory treatments for IVD degeneration.