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Poly-L-lactic acid (PLLA) implants have been used for bone fixation for decades. However, upon insertion, they can cause a foreign body reaction (FBR) that may lead to complications. On 15 December 2023, a systematic review was conducted to search for articles on the PubMed, MeSH term, and Scopus databases using the keywords ‘PLLA’ and ‘foreign body reaction’. The articles were reviewed not only for the question of FBR, its severity, and the manifestation of symptoms but also for the type of implant and its location in the body, the species, and the number of individuals included. A total of 71 original articles were identified. Of these, two-thirds reported on in vivo trials, and one-third reported on clinical applications. The overall majority of the reactions were mild in more than half of the investigations. Symptoms of extreme and extensive FBR mainly include osteolysis, ganglion cysts, and swelling. The localization of PLLA implants in bone can often result in osteolysis due to local acidosis. This issue can be mitigated by adding hydroxyapatite. There should be no strong FBR when PLLA is fragmented to 0.5–4 µm by extracorporeal shock wave.

Background: There is a strong interest in designing new scaffolds for their potential application in tissue engineering and regenerative medicine. The incorporation of functionalization molecules can lead to the enhancement of scaffold properties, resulting in variations in scaffold compatibility. Therefore, the efficacy of the therapy could be compromised by the foreign body reaction triggered after implantation.Methods: In this study, the biocompatibilities of three scaffolds made from an alginate–chitosan combination and functionalized with gold nanoparticles (AuNp) and alginate-coated gold nanoparticles (AuNp + Alg) were evaluated in a subcutaneous implantation model in Wistar rats. Scaffolds and surrounding tissue were collected at 4-, 7- and 25-day postimplantation and processed for histological analysis and quantification of the expression of genes involved in angiogenesis, macrophage profile, and proinflammatory (IL-1β and TNFα) and anti-inflammatory (IL-4 and IL-10) cytokines.Results: Histological analysis showed a characteristic foreign body response that resolved 25 days postimplantation. The intensity of the reaction assessed through capsule thickness was similar among groups. Functionalizing the device with AuNp and AuNp + Alg decreased the expression of markers associated with cell death by apoptosis and polymorphonuclear leukocyte recruitment, suggesting increased compatibility with the host tissue. Similarly, the formation of many foreign body giant cells was prevented. Finally, an increased detection of alpha smooth muscle actin was observed, showing the angiogenic properties of the elaborated scaffolds.Conclusion: Our results show that the proposed scaffolds have improved biocompatibility and exhibit promising potential as biomaterials for elaborating tissue engineering constructs.

Tissue penetrating microelectrode neural probes can record electrophysiological brain signals at resolutions down to single neurons, making them invaluable tools for neuroscience research and Brain-Computer-Interfaces (BCIs). The known gradual decrease of their electrical interfacing performances in chronic settings, however, remains a major challenge. A key factor leading to such decay is Foreign Body Reaction (FBR), which is the cascade of biological responses that occurs in the brain in the presence of a tissue damaging artificial device. Interestingly, the recent adoption of Complementary Metal Oxide Semiconductor (CMOS) technology to realize implantable neural probes capable of monitoring hundreds to thousands of neurons simultaneously, may open new opportunities to face the FBR challenge. Indeed, this shift from passive Micro Electro-Mechanical Systems (MEMS) to active CMOS neural probe technologies creates important, yet unexplored, opportunities to tune probe features such as the mechanical properties of the probe, its layout, size, and surface physicochemical properties, to minimize tissue damage and consequently FBR. Here, we will first review relevant literature on FBR to provide a better understanding of the processes and sources underlying this tissue response. Methods to assess FBR will be described, including conventional approaches based on the imaging of biomarkers, and more recent transcriptomics technologies. Then, we will consider emerging opportunities offered by the features of CMOS probes. Finally, we will describe a prototypical neural probe that may meet the needs for advancing clinical BCIs, and we propose axial insertion force as a potential metric to assess the influence of probe features on acute tissue damage and to control the implantation procedure to minimize iatrogenic injury and subsequent FBR.

Macrophage polarization is a significant event in the host immune response, which can be modulated by modifying the surface of a biomaterial. Previous studies have demonstrated the modulation of macrophage polarization using different surface features; however, none of these studies reflect the effect of surface properties on unstimulated macrophage polarization for a prolonged period. To better understand the impact of surface features, in this work differentiated THP‐1 cells are employed to control macrophage polarization on nano‐rough surfaces for a duration of 7 days. Model nano‐rough substrates are fabricated by immobilizing gold nanoparticles (AuNPs) of predetermined sizes (16, 38, 68 nm) on a 2‐methyl‐2‐oxazoline thin film, followed by tailoring the outermost surface chemistry. All modified surfaces support high levels of cell adhesion and proliferation. Over time, the expression of pro‐inflammatory cytokines decreases, whereas the expression of anti‐inflammatory cytokines increases on all modified surfaces. Similarly, pro‐inflammatory interleukin (IL)‐1β gene expression is downregulated, and anti‐inflammatory IL‐10‐gene expression is upregulated, regardless of the surface roughness. Analysis of cell morphology reveals that the predominant cell type on the modified surfaces exhibits M2 anti‐inflammatory phenotype. Herein, how surface features can modulate macrophage responses over an extended period is highlighted, offering insights for the development of future biomaterial implants.

Biomaterials, when implanted in the human body, can induce a series of cell- and cytokine-related reactions termed foreign body reactions (FBRs). In the progression of FBRs, macrophages regulate inflammation and healing by polarizing to either a pro-inflammatory or pro-healing phenotype and recruit fibroblasts by secreting cytokines. Stimulated by the biomaterials, fibrotic capsule is formed eventually. The implant, along with its newly formed capsule, introduces various mechanical cues that influence cellular functions. Mechanosensing proteins, such as integrins or ion channels, transduce extracellular mechanical signals into cytoplasm biochemical signals in response to mechanical stimuli. Consequently, the morphology, migration mode, function, and polarization state of the cells are affected. Modulated by different intracellular signaling pathways and their crosstalk, the expression of fibrotic genes increases with fibroblast activation and fibroblast to myofibroblast transition under stiff or force stimuli. However, summarized in most current studies, the outcomes of macrophage polarization in the effect of different mechanical cues are inconsistent. The underlying mechanisms should be investigated with more advanced technology and considering more interfering aspects. Further research is needed to determine how to modulate the progression of fibrotic capsule formation in FBR artificially.

Spinal fusion surgery is a common procedure used to stabilize the spine and treat back pain. The procedure involves the use of foreign materials such as screws, rods, or cages, which can trigger a foreign body reaction, an immune response that involves the activation of immune cells such as macrophages and lymphocytes. The foreign body reaction can impact the success of spinal fusion, as it can interfere with bone growth and fusion. This review article provides an overview of the cellular and molecular events in the foreign body reaction, the impact of the immune response on spinal fusion, and strategies to minimize its impact. By carefully considering the use of foreign materials and optimizing surgical techniques, the impact of the foreign body reaction can be reduced, leading to better outcomes for patients.

Background: Vesicoureteral junction (VUJ) obstruction after Deflux® subureteral injection for vesicoureteral reflux (VUR) is rare and minimally invasive management has not been reported. This work investigated the patients who underwent Deflux® injection for VUR and identified those with subsequent VUJ obstruction. Methods: Medical records of matched patients from October 2003 to March 2022 were reviewed, and parameters were retrospectively studied. All patients underwent Deflux® injection. The injection was performed under general anesthesia using the same manner. For patients complicated with VUJ obstruction, the symptoms, signs, management, images, renal ultrasounds, Tc-99m dimercaptosuccinic acid renal scintigraphy, histology of VUJ region, and outcomes were documented and reported. VUJ stenosis was diagnosed by performing renal ultrasound and magnetic resonance imaging. Results: Totally 407 patients (554 ureterorenal units) received Dx/HA injections for VUR. VUJ obstruction was found in three patients (four ureterorenal units). Originally, three were grade V VUR, and one was grade IV. The repeated injection was not a risk factor for VUJ obstruction. The overall incidence of VUJ obstruction post-Dx/HA injection was 0.7% by ureter. The incidences were 0%, 0.75%, and 2.25% for grade I–III, IV, and V VUR, respectively. After the initial conversion case of pneumovesicoscopic ureteral reimplantation, the procedure was performed smoothly and successfully in the two following cases. Conclusions: Pneumovesicoscopic ureteral reimplantation offers an alternative for VUJ obstruction following Dx/HA injection for VUR. Fibrosis and foreign-body reaction may influence the feasibility. High-grade VUR and young age of injection were related to VUJ obstruction. [ABSTRACT FROM AUTHOR]

Our patient underwent several endoscopic treatments with balloon dilatation and even tandem stent placement; however, despite this, the patient's symptoms persisted, and a CT scan showed ongoing mild hydronephrosis. Abbreviations eGFR estimated GFR KUB kidneys, ureters and bladder NT nephrostomy tube PCNL percutaneous nephrolithotomy RIRS retrograde intrarenal surgery SWL shockwave lithotripsy URS ureteroscopy Introduction Urinary calculi are a challenging global illness with an increased reported incidence in the last few decades. "Case of the Month" from the University of British Columbia, Vancouver, Canada: impacted ureteric stone: management of a stricture complication and the role of minimally invasive surgery. [Extracted from the article]

Background: The aim of this study was to establish a sheep model of the Puricelli biconvex arthroplasty (ABiP) technique in sheep for evaluating its functional, biological and histological parameters. Methods: Ten Corriedale black sheep were submitted to TMJ total reconstruction with poly(methyl methacrylate) (PMMA) using ABiP and euthanized after 45 (n = 5) or 90 (n = 5) days. Control animals (n = 2) underwent sham operations and were euthanized after 45 days. Variables were assessed before the surgery (T0), immediately after (T1) and at 45 or 90 postoperative days (T2). Results: Histological analyses showed regression of inflammatory cells over the follow-up period. PMMA showed reduced porosity and roughness in the articular contact area. PMMA temporal components showed linear and volumetric wear in comparison to control, but no foreign body reaction was observed. The reconstructions were stable in all animals. The amplitude of mouth opening and left lateral movements were maintained, except for a reduction in the range of right lateral movements at day 90 in the experimental group. Clinical, macroscopic and radiographic observations showed that the reconstructions were stable. Conclusions: The analysis of functional, biological and histological parameters in sheep submitted to ABiP showed stable results of the procedure, with maintenance of body weight and all mandibular movements, save contralateral mandibular movement, suggesting that joint function was completely maintained following the procedure. This experimental study provides support for clinical results previously reported of the ABiP technique in TMJ reconstruction procedures. [ABSTRACT FROM AUTHOR]

High efficiency of hybrid implants based on calcium-magnesium silicate ceramic, diopside, as a carrier of recombinant BMP-2 and xenogenic demineralized bone matrix (DBM) as a scaffold for bone tissue regeneration was demonstrated previously using the model of critical size cranial defects in mice. In order to investigate the possibility of using these implants for growing autologous bone tissue using in vivo bioreactor principle in the patient's own body, effectiveness of ectopic osteogenesis induced by them in intramuscular implantation in mice was studied. At the dose of 7 μg of BMP-2 per implant, dense agglomeration of cells, probably skeletal muscle satellite precursor cells, was observed one week after implantation with areas of intense chondrogenesis, initial stage of indirect osteogenesis, around the implants. After 12 weeks, a dense bone capsule of trabecular structure was formed covered with periosteum and mature bone marrow located in the spaces between the trabeculae. The capsule volume was about 8-10 times the volume of the original implant. There were practically no signs of inflammation and foreign body reaction. Microcomputed tomography data showed significant increase of the relative bone volume, number of trabeculae, and bone tissue density in the group of mice with BMP-2-containing implant in comparison with the group without BMP-2. Considering that DBM can be obtained in practically unlimited quantities with required size and shape, and that BMP-2 is obtained by synthesis in E. coli cells and is relatively inexpensive, further development of the in vivo bioreactor model based on the hybrid implants constructed from BMP-2, diopside, and xenogenic DBM seems promising. [ABSTRACT FROM AUTHOR]

This graphical abstract was created by Adobe Photoshop 2020 containing the rat and muscle materials from BioRender.com. [Display omitted] Brexpiprazole (BPZ), which is approved for the treatment of schizophrenia and major depressive disorder, has the potential to meet diverse clinical needs. This study aimed to develop a long-acting injectable (LAI) formulation of BPZ that could provide sustained therapeutic benefits. A library of BPZ prodrugs was screened through esterification, and BPZ laurate (BPZL) was identified as an optimal candidate. To achieve stable aqueous suspensions, a pressure- and nozzle size-controlled microfluidization homogenizer was utilized. The pharmacokinetics (PK) profiles, considering dose and particle size modulation, were investigated following a single intramuscular injection in beagles and rats. BPZL treatment resulted in sustained plasma concentrations above the median effective concentration (EC 50) for 2 ∼ 3 weeks, without exhibiting an initial burst release. Histological examination of foreign body reaction (FBR) in rats revealed the morphological evolution of an inflammation-mediated drug depot, confirming the sustained release mechanism of BPZL. These findings provide strong support for the further development of a ready-to-use LAI suspension of BPZL, which could potentially enhance treatment outcomes, improve patient adherence, and address the clinical challenges associated with long-term regimens of schizophrenia spectrum disorders (SSD). [ABSTRACT FROM AUTHOR]

(1) Background: The demands of patients for aesthetic and functional rehabilitation of edentulous areas led to the use of dental implants as therapeutic means on an increasingly large scale. This aspect determined the appearance of some infectious pathologies with a peri-implant starting point that can be complicated by various sinus diseases. The purpose of this review article is to synthesize the existing information in the specialized literature regarding the existing correlations between peri-implant and maxillary sinusitis. (2) Methods: The articles published in five databases were researched using different combinations of search terms. We selected 12 articles from the 250 found, by applying the inclusion and exclusion criteria and removing duplicates. (3) Results: We analyzed the included studies and we found that all of them reported a positive correlation between maxillary sinusitis and peri-implant infectious diseases. There are also reported other pathologies with a peri-implant infectious disease as a starting point such as abscesses, oro-antral communications, or foreign body reactions due to implant or bone graft materials migration. (4) Conclusions: This scoping review highlighted the existence of correlations between peri-implant and sinus pathology and the importance of preventing peri-implant diseases of an infectious nature to avoid the occurrence of these complications. [ABSTRACT FROM AUTHOR]

Dogs are curious by nature; they love to investigate new sights, smells and tastes. Unfortunately this usually leads them in to trouble, by causing foreign body ingestion and subsequent complications like alimentary tract obstruction and perforation. 'Pica' is another important reason for foreign body ingestion, especially in puppies. A gastric/enteric foreign body is anything that is ingested by an animal that cannot be digested, which eventually may cause obstruction. This is an evaluative report of four different cases of foreign body ingestion in dogs and its successful surgical management. Four canine patients belonging to different age groups, diagnosed (through radiography) with foreign body ingestion were subjected to laparotomy (gastrotomy/enterotomy) under general anaesthesia. A fish hook, an open safety pin, an aquarium pebble and a metal vessel lid were the objects recovered from these patients individually. Irrespective of recovery site, all patients exhibited acute vomiting as a common symptom. With timely and precise diagnosis, surgical intervention and post-operative management, all patients showed a complete, uneventful recovery post-surgery. This report notes that ingested foreign bodies (especially penetrating type) in dogs should always be considered as an emergency and can be surgically managed in field with great success rate. [ABSTRACT FROM AUTHOR]

Background: There is an increasing number of patients following hernia surgery with implanted mesh reporting symptoms that could indicate autoimmune or allergic reactions to mesh. 'Allergy' to metals, various drugs, and chemicals is well recognised. However, hypersensitivity, allergy or autoimmunity caused by surgical mesh has not been proven by a scientific method to date. The aim of this study was twofold: to describe the pathophysiology of autoimmunity and foreign body reaction and to undertake a systematic review of surgical mesh implanted at the time of hernia repair and the subsequent development of autoimmune disease. Methods: A systematic review using the PRISMA guidelines was undertaken. Pubmed (Medline), Google Scholar and Cochrane databases were searched for all English-written peer-reviewed articles published between 2000 and 2021. The search was performed using the keywords "hernia", "mesh", "autoimmunity", "ASIA", "immune response", "autoimmune response". Results: Seven papers were included in the final analysis—three systematic reviews, three cohort studies and one case report. Much of the current data regarding the association of hernia mesh and autoimmunity relies on retrospective cohort studies and/or case reports with limited availability of cofounding factor data linked to autoimmune disease such as smoking status or indeed a detailed medical history of patients. Three systematic reviews have discussed this topic, each with a slightly different approach and none of them has identified causality between the use of mesh and the subsequent development of autoimmune disease. Conclusion: There is little evidence that the use of polypropylene mesh can lead to autoimmunity. A large number of potential triggers of autoimmunity along with the genetic predisposition to autoimmune disease and the commonality of hernia, make a cause and effect difficult to unravel at present. Biomaterials cause foreign body reactions, but a chronic foreign body reaction does not indicate autoimmunity, a common misunderstanding in the literature. [ABSTRACT FROM AUTHOR]

Biodegradable hydrogels are growing in demand to enable the delivery of biomolecules (e.g. growth factors) for regenerative medicine. This research investigated the resorption of an oligourethane/polyacrylic acid hydrogel, a biodegradable hydrogel which supports tissue regeneration. The Arrhenius model was used to characterize the resorption of the polymeric gels in relevant in vitro conditions, and the Flory-Rehner equation was used to correlate the volumetric swelling ratio with the extent of degradation. The study found that the swelling rate of the hydrogel follows the Arrhenius model at elevated temperatures, estimating degradation time in saline solution at 37°C to be between 5 and 13 months, serving as a preliminary approximation of degradation in vivo. The degradation products had low cytotoxicity towards endothelial cells, and the hydrogel supported stromal cell proliferation. Additionally, the hydrogels were able to release growth factors and maintain the biomolecules' bioactivity towards cell proliferation. The study of the vascular endothelial growth factor (VEGF) release from the hydrogel used a diffusion process model, showing that the electrostatic attraction between VEGF and the anionic hydrogel allowed for controlled and sustained VEGF release over three weeks. In a rat subcutaneous implant model, a selected hydrogel with desired degradation rates exhibited minimal foreign body response and supported M2a macrophage phenotype, and vascularization. The low M1 and high M2a macrophage phenotypes within the implants were associated with tissue integration. This research supports the use of oligourethane/polyacrylic acid hydrogels as a promising material for delivering growth factors and supporting tissue regeneration. There is a need for degradable elastomeric hydrogels that can support the formation of soft tissues and minimize long-term foreign body responses. An Arrhenius model was used to estimate the relative breakdown of hydrogels, in-vitro. The results demonstrate that hydrogels made from a combination of poly(acrylic acid) and oligo-urethane diacrylates can be designed to resorb over defined periods ranging from months to years depending on the chemical formulation prescribed by the model. The hydrogel formulations also provided for different release profiles of growth factors, relevant to tissue regeneration. In-vivo , these hydrogels had minimal inflammatory effects and showed evidence of integration into the surrounding tissue. The hydrogel approach can help the field design a broader range of biomaterials for tissue regeneration. [Display omitted] [ABSTRACT FROM AUTHOR]

Precision porous templated scaffolds (PTS) are a hydrogel construct of uniformly sized interconnected spherical pores that induce a pro-healing response (reducing the foreign body reaction, FBR) exclusively when the pores are 30-40µm in diameter. Our previous work demonstrated the necessity of T regs in the maintenance of PTS pore size specific differences in CD4+ T cell phenotype. Work here characterizes the role of T regs in the responses to implanted 40µm and 100µm PTS using WT and FoxP3+ cell (T reg) depleted mice. Proteomic analyses indicate that integrin signaling, monocytes/macrophages, cytoskeletal remodeling, inflammatory cues, and vesicule endocytosis may participate in T reg activation and the CD4+ T cell equilibrium modulated by PTS resident cell-derived small extracellular vesicles (sEVs). The role of MyD88-dependent and MyD88-independent TLR4 activation in PTS cell-derived sEV-to-T cell signaling is quantified by treating WT, TLR4ko, and MyD88ko splenic T cells with PTS cell-derived sEVs. STAT3 and mTOR are identified as mechanisms for further study for pore-size dependent PTS cell-derived sEV-to-T cell signaling. Unique cell populations colonizing only within 40µm pore size PTS generate sEVs that resolve inflammation by modifying CD4+ T cell phenotypes through TLR4 signaling. [Display omitted] [ABSTRACT FROM AUTHOR]

Despite great success with artificial implants for the human body, modern implants cannot solve major health problems. The reason is an immune reaction of organisms to artificial implants, known as the foreign body reaction. We have found a way to avoid or decrease the foreign body reaction. The surface of an artificial implant is modified with condensed aromatic structures containing free radicals, which provide a covalent attachment of host proteins in a native conformation. The total protein coverage prevents the direct contact of immune cells with the implant surface, and the immune cells are not activated. As a result, the immune response of the organism is not generated, and the artificial implant is not isolated from the tissue; there is no collagen capsule, low activity of macrophages, low cell proliferation, and low inflammatory activity. [ABSTRACT FROM AUTHOR]

Soft and stretchable electronics have emerged as highly promising tools for biomedical diagnosis and biological studies, as they interface intimately with the human body and other biological systems. Most stretchable electronic materials and devices, however, still have Young's moduli orders of magnitude higher than soft bio-tissues, which limit their conformability and long-term biocompatibility. Here, we present a design strategy of soft interlayer for allowing the use of existing stretchable materials of relatively high moduli to versatilely realize stretchable devices with ultralow tissue-level moduli. We have demonstrated stretchable transistor arrays and active-matrix circuits with moduli below 10 kPa—over two orders of magnitude lower than the current state of the art. Benefiting from the increased conformability to irregular and dynamic surfaces, the ultrasoft device created with the soft interlayer design realizes electrophysiological recording on an isolated heart with high adaptability, spatial stability, and minimal influence on ventricle pressure. In vivo biocompatibility tests also demonstrate the benefit of suppressing foreign-body responses for long-term implantation. With its general applicability to diverse materials and devices, this soft-interlayer design overcomes the material-level limitation for imparting tissue-level softness to a variety of bioelectronic devices. Stretchable electronics are attractive for a range of biomedical applications, but are challenging to prepare with suitable mechanical properties. Here, the authors report the use of a soft interlayer that allows the development of stretchable electronics with tissue-like material properties. [ABSTRACT FROM AUTHOR]

Simple Summary: Giant cells (GCs) are found in many different tissues and among different backgrounds, including reactive, and neoplastic settings. It is not yet fully understood whether GCs in similar settings or with related functions share the same surface antigen expression. We performed antigen profiling of GCs via immunohistochemistry in multiple reactive and neoplastic lesions. We were able to characterise distinct groups of GCs with similar expression patterns, as well as GCs in some lesions that had a unique antigen expression pattern. These findings may help in the diagnosis of histologically similar GC-rich lesions and provide further insight into the function and origin of these cells. Giant cells (GCs) are thought to originate from the fusion of monocytic lineage cells and arise amid multiple backgrounds. To compare GCs of different origins, we immunohistochemically characterised the GCs of reactive and neoplastic lesions (n = 47). We studied the expression of 15 molecules including HLA class II molecules those relevant to the cell cycle, bone metabolism and lineage affiliation. HLA-DR was detectable in the GCs of sarcoidosis, sarcoid-like lesions, tuberculosis, and foreign body granuloma. Cyclin D1 was expressed by the GCs of neoplastic lesions as well as the GCs of bony callus, fibroid epulis, and brown tumours. While cyclin E was detected in the GCs of all lesions, p16 and p21 showed a heterogeneous expression pattern. RANK was expressed by the GCs of all lesions except sarcoid-like lesions and xanthogranuloma. All GCs were RANK-L-negative, and the GCs of all lesions were osteoprotegerin-positive. Osteonectin was limited to the GCs of chondroblastoma. Osteopontin and TRAP were detected in the GCs of all lesions except xanthogranuloma. RUNX2 was heterogeneously expressed in the reactive and neoplastic cohort. The GCs of all lesions except foreign body granuloma expressed CD68, and all GCs were CD163- and langerin-negative. This profiling points to a functional diversity of GCs despite their similar morphology. [ABSTRACT FROM AUTHOR]

BACKGROUND: Fibrous capsules (Fb) in response to cardiovascular implantable electronic devices (CIEDs), including a pacemaker (P) system, can produce patient discomfort and difficulties in revision surgery due partially to their increased compressive strength, previously linked to elevated tissue fibers. OBJECTIVE: A preliminary study to quantify structural proteins, determine if biologic extracellular matrix-enveloped CIEDs (PECM) caused differential Fb properties, and to implement a realistic mechanical model. METHODS: Retrieved Fb (-P and -PECM) from minipigs were subjected to biomechanical (shear oscillation and uniaxial compression) and histological (collagen I and elastin) analyses. RESULTS: Fb-PECM showed significant decreases compared to Fb-P in: low strain-loss modulus (390 vs. 541 Pa) across angular frequencies, high strain-compressive elastic modulus (1043 vs. 2042 kPa), and elastic fiber content (1.92 vs. 3.15 μg/mg tissue). Decreases in elastin were particularly noted closer to the implant's surface (Fb-PECM = 71% vs. Fb-P = 143% relative to dermal elastin at mid-tangential sections) and verified with a solid mechanics hyperelasticity with direction-dependent fiber viscoelasticity compression simulation (r2 ≥ 98.9%). CONCLUSIONS: The biologic envelope composed of decellularized porcine small intestine submucosa ECM for CIEDs promoted fibrous tissues with less elastic fibers. Novel compression modeling analyses directly correlated this singular reduction to more desirable subcutaneous tissue mechanics. [ABSTRACT FROM AUTHOR]

Objectives: Septic non-union in long-bone fractures represents a challenging clinical entity. Management of lower extremity segmental bone defects, aiming to restore functional anatomy, remains extremely difficult and controversial. Masquelet technique is a reconstruction method for large diaphyseal bone defects, based on the notion of the induced membrane. The principle of the induced membrane is to create a foreign body reaction by placing cement spacer in the bone defect. The purpose of this study was to assess the success rate of induced membrane technique (IMT) in treating lower extremity large bone defects due to septic non-union. Methods: This is a retrospective observational study performed in a single referral center in France, Europe, which is specialized in complex bone and joint infections. All patients operated for septic non-union were identified from a prospectively maintained database. Patients treated with the IMT for septic femoral or tibial non-union between 2013 and 2017 were enrolled in this study. Exclusion criteria were infection of a continuous bone, aseptic non-union, or patients with less than one year of follow-up after antibiotic treatment ending. Results: Twenty-three cases (19 patients) with an average age of 41.3 years were included in the present study. There were 19 tibial and four femoral fractures. The mean bone defect was 65.3 mm. The mean time interval from initial trauma to the first surgical phase was 17 months, while that between the two surgical phases was 77.7 days. After the first surgical phase, samples were positive in 13 cases (68.5%), isolating Staphylococcus (26%) and more than one pathogen in 22% of cases. Bone union was successful in 16 of 23 cases (69.6%, 14 patients). There were seven failures: five amputations due to mechanical and/or infection-related failure and two failed unions. Conclusion: This study found that 69% of cases with septic non-union of tibial or femoral fracture treated with the two-step surgical protocol achieved bone union and infection eradication within about 13.2 months after the second stage of the procedure. The study revealed promising results in patients suffering large-size bone defect; hence, the IMT may prove beneficial in the management of such cases. [ABSTRACT FROM AUTHOR]

To assess the immune potential of spiders, in the present study juvenile and adult females of Parasteatoda tepidariorum were exposed to Bacillus subtilis infection, injury by a nylon monofilament and a combination of both. The expression level of selected immune-related genes: defensin 1 (PtDEF1), lysozyme 1 (PtLYS1), lysozyme C (PtLYSC), lysozyme M1 (PtLYSM1), autophagy-related protein 101 (PtATG101), dynamin (PtDYN) and heat shock proteins (HSP70) (PtHSPB, PtHSPB2A, PtHSPB2B), production of lysozyme and HSP70 proteins, and hemocytes viability were measured. The obtained results indicated expression of the lysozyme, autophagy-related protein and HSP70 genes in both ontogenetic stages of P. tepidariorum. It has been also shown that the simultaneous action of mechanical and biological factors causes higher level of lysozyme and HSP70, cell apoptosis intensity and lower level of hemocytes viability than in the case of exposure to a single immunostimulant. Moreover, mature females showed stronger early immune responses compared to juveniles. [ABSTRACT FROM AUTHOR]

Background: Synthetic mesh material is of great importance for surgical incisional hernia repair. The physical and biochemical characteristics of the mesh influence mechanical stability and the foreign body tissue reaction. The influence on bacterial infections, however, remains ill-defined. The aim of the present study was to evaluate the influence of a modified mesh structure with variation in filament linking on the occurrence of bacterial infection that is indicated by the occurrence of CD68+, CD4+, and CD8+ cells in two different materials. Methods: A total of 56 male Sprague Dawley rats received a surgical mesh implant in a subcutaneous abdominal position. The mesh of two different polymers (polypropylene (PP) and polyvinylidenfluoride (PVDF)) and two different structures (standard structure and bold structure with higher filament linking) were compared. During the implantation, the meshes were infected with Staphylococcus (S.) aureus. After 7 and 21 days, meshes were explanted, and the early and late tissue responses to infection were histologically evaluated. Results: Overall, the inflammatory tissue response was higher at 7 days when compared to 21 days. At 7 days, PP meshes of the standard structure (PP-S) showed the strongest inflammatory tissue response in comparison to all the other groups. At 21 days, no statistically significant difference between different meshes was detected. CD8+ cytotoxic T cells showed a significant difference at 21 days but not at 7 days. PP meshes of both structures showed a higher infiltration of CD8+ T cells than PVDF meshes. CD4+ T helper cells differed at 7 days but not at 21 days, and PVDF meshes in a bold structure showed the highest CD4+ T cell count. The number of CD68+ macrophages was also significantly higher in PP meshes in a standard structure when compared to PVDF meshes at 21 days. Conclusion: The inflammatory tissue response to S. aureus infection appears to be highest during the early period after mesh implantation. PP meshes showed a higher inflammatory response than PVDF meshes. The mesh material appears to be more important for the risk of infection than the variation in filament linking. [ABSTRACT FROM AUTHOR]

By studying the local effects of a new type of injectable cosmetic filler implanted into the animal to explore the mechanism of remodeling and cosmetic effect of this kind of product. Take 12 rabbits and select 4 implantation points on both sides of the spine, respectively, and implant the test sample (PLLA) and negative control sample (HDPE) into the subcutaneous tissues on both sides. In the same way, take another 12 rabbits and implant the marketing control sample (cross-linked sodium hyaluronate) and negative control sample (HDPE) into the subcutaneous tissues on both sides. The animals were executed at 1 week, 4 weeks, 13 weeks and 52 weeks respectively, and Hematoxylin–Eosin staining, Masson trichrome staining and immunofluorescence staining were performed to characterize the local effects in vivo and the expression of type I collagen (Col. I), type III collagen (Col.III) and matrix metalloproteinase 9 (MMP-9). Good histocompatibility of the test sample and the marketing control sample were found. The foreign body reaction of marketing control sample was more intense than that of the test sample after 13 weeks. The foreign body reaction of testing sample was more intense after 52 weeks, while that of the marketing control sample was more stable. With the process of tissue repair, the collagen fibers of test samples and marketing control samples gradually increased after implantation. Type I collagen was mainly found inside the fiber capsule, while type III collagen was mainly found outside. The positive expression of matrix metalloproteinase 9 gradually increased, the positive expression of test samples increased significantly after 52 weeks, while that of marketing control samples did not change significantly. Good histocompatibility of PLLA filler is found. Matrix metalloproteinase 9 participates in foreign body reaction and collagen formation, which can reflect the process of tissue remodeling. [ABSTRACT FROM AUTHOR]

Mg alloys have mechanical properties compatible with human bones. However, their rapid degradation and associated foreign body reactions in vivo significantly limit their application for human implants. In this study, three differently processed Mg alloys, pure Mg (PM), cold extruded Mg alloy AZ31 (CE AZ31), and fully annealed AZ31 Mg alloy (FA AZ31) were comparatively investigated for their potential as implants using a rat model. All three implanted Mg alloys do not show any impact on hepato- and renal function, nor any signs of observable changes to vital organs. Proteomics analysis of tissues directly contacting the implants 2.5 months post implantation revealed that FA AZ31 activates very few inflammation and immune associated signaling pathways; while the CE AZ31 and PM produce more significant inflammatory responses as confirmed by cytokine array analyses. Further, FA AZ31 activated pathways for cell organization and development that may improve the recovery of injured tissues. Structurally, EBSD analysis reveals that the FA AZ31 alloy has a higher ratio of first-order pyramidal orientated (10–11){10–1–2} grain texture with a value of 0.25, while PM and CE AZ31 alloys have lower ratios of first-order pyramidal orientated texture with the values of 0.16 and 0.17, respectively. This is associated with recovery and recrystallisation during annealing which promotes grain texture which exhibits enhanced degradation behaviours and induces a more limited immune response in vivo. In conclusion, the FA AZ31 demonstrated better biocompatibility and corrosion resistance and is a promising candidate for metal-based degradable implants which warrants further investigation. [ABSTRACT FROM AUTHOR]

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With the advances in understanding the relationships among biomaterials, the immune system and the skeletal system, the host responses elicited by implanted biomaterials can be balanced by properly designing material characteristics from the perspective of osteoimmunology. The immunoregulatory properties of bone tissue engineering scaffolds provide advantages for inducing macrophages from the proinflammatory M1 phenotype to the anti-inflammatory M2 phenotype and promoting osseointegration. Hydrogels are increasingly a focus in bone tissue engineering, and the immune response can be affected by different compositions of hydrogels, such as the sources, concentration, molecular weight, coupling with fibronectin, and the addition of cross-linking agents. Different physicochemical properties of modified hydrogels can trigger different host immune responses, modified by using soft photolithography to fabricate micropatterned hydrogels, adding enzyme-sensitive sequences, ester bonds and dynamic covalent chemistry to prevent rapid or slow degradation of the hydrogels, and adding porogens and 3D printing to modify the hydrogels with macroporous interconnective pore structures, soft and injectable hydrogels, etc. These optimized hydrogels can reduce proinflammatory factors, promote M2 macrophage polarization, and minimize foreign body reactions to evoke bone regeneration. However, the mechanism underlying the bone immune response is still poorly understood, and further study of the effects of hydrogels with different physicochemical properties on immune regulation is needed.

Abstract Background The poly-d, l-lactic acid absorbable plate does not contain poly l-lactic acid, which is the main factor in foreign body reactions; therefore, with use of this plate, a foreign body reaction is unlikely. In fact, few reports have been published on removal of a poly-d, l-lactic acid absorbable plate owing to a foreign body reaction. Case presentation We report a case of abscess formation that led finally to the removal of a poly-d, l-lactic acid absorbable plate. A 45-years-old man with a left zygomaticomaxillary complex fracture sustained during a fall underwent open reduction using the poly-d, l-lactic acid absorbable plate. Fourteen months after the operation, he was admitted to our hospital with swelling and redness of the left lateral part of the upper eyelid. Upon incision of the swelling, we found a large amount of purulent drainage and the plate in broken fragments and removed as many of the fragments as possible. The swelling was improved after drainage of the incision twice and use of antibiotics, and the bacterial culture results were negative. No recurrence or aggravation was observed after the drainage. Conclusions We suspected sterile abscess formation secondary to a foreign body reaction to the poly-d, l-lactic acid absorbable plate. Given that the poly-d, l-lactic acid absorbable plate is absorbed over a period of more than 1 year postoperatively, long-term follow-up of injuries treated using the plate may be required. Furthermore, surgical intervention, such as drainage or removal, should be considered if the foreign body reaction symptoms are severe.

The production of a cellularized silk fibroin scaffold is very difficult because it is actually impossible to differentiate cells into a well-organized cardiac tissue. Without vascularization, not only do cell masses fail to grow, but they may also exhibit an area of necrosis, indicating a lack of oxygen and nutrients. In the present study, we used the so-called tyrosine protein kinase kit (c-Kit)-positive cardiac progenitor cells (CPCs) to generate cardiac cellularized silk fibroin scaffolds, multipotent cells isolated from the adult heart to date that can show some degree of differentiation toward the cardiac phenotype. To test their ability to differentiate into the cardiac phenotype in vivo as well, CPC and collagen organoid-like masses were implanted into nude mice and their behavior observed. Since the 3-dimensional structure of cardiac tissue can be preserved by scaffolds, we prepared in parallel different silk fibroin scaffolds with 3 different geometries and tested their behavior in 3 different models of immunosuppressed animals. Unfortunately, CPC cellularized silk fibroin scaffolds cannot be used in vivo. CPCs implanted alone or in collagen type I gel were destroyed by CD3+ lymphocyte aggregates, whereas the porous and partially oriented scaffolds elicited a consistent foreign body response characterized by giant cells. Only the electrospun meshes were resistant to the foreign body reaction. In conclusion, c-Kit-positive CPCs, although expressing a good level of cardiac differentiation markers in vitro with or without fibroin meshes, are not suitable for an in vivo model of cardiac organoids because they are degraded by a T-cell-mediated immune response. Even scaffolds which may preserve the survival of these cells in vivo also induced a host response. However, among the tested scaffolds, the electrospun meshes (F-scaffold) induced a lower response compared to all the other tested structures. [ABSTRACT FROM AUTHOR]

Oral pulse granuloma is a rare lesion of the oral cavity with unclear etiology. Some authors believe this lesion is a foreign body reaction to implanted food particles. In the oral cavity, most cases are found in the posterior regions of the mandible. The edentulous mandible was involved in 20 cases with oral pulse granuloma. In these cases, the premolar–molar site was the most common region. Here we present a case of a 70-year-old male with huge unilateral swelling of the mandible on the left side. This paper aims to present a case of oral pulse granuloma with wide extension, detailed clinicohistopathologic features with 2-year follow-up and a short review of reported cases. [ABSTRACT FROM AUTHOR]

Biomaterials are implanted in millions of individuals worldwide each year. Both naturally derived and synthetic biomaterials induce a foreign body reaction that often culminates in fibrotic encapsulation and reduced functional lifespan. In ophthalmology, glaucoma drainage implants (GDIs) are implanted in the eye to reduce intraocular pressure (IOP) in order to prevent glaucoma progression and vision loss. Despite recent efforts towards miniaturization and surface chemistry modification, clinically available GDIs are susceptible to high rates of fibrosis and surgical failure. Here, we describe the development of synthetic, nanofiber‐based GDIs with partially degradable inner cores. We evaluated GDIs with nanofiber or smooth surfaces to investigate the effect of surface topography on implant performance. We observed in vitro that nanofiber surfaces supported fibroblast integration and quiescence, even in the presence of pro‐fibrotic signals, compared to smooth surfaces. In rabbit eyes, GDIs with a nanofiber architecture were biocompatible, prevented hypotony, and provided a volumetric aqueous outflow comparable to commercially available GDIs, though with significantly reduced fibrotic encapsulation and expression of key fibrotic markers in the surrounding tissue. We propose that the physical cues provided by the surface of the nanofiber‐based GDIs mimic healthy extracellular matrix structure, mitigating fibroblast activation and potentially extending functional GDI lifespan. [ABSTRACT FROM AUTHOR]

The purposes of this article are to report the clinical case of a patient who exhibited a foreign body reaction associated with the use of bone wax after extraction of an impacted third molar and to present an integrative literature review addressing the possible influences of this hemostatic agent on bone healing. A 26-year-old woman who underwent the extraction of her mandibular right third molar developed intense alveolar bleeding during surgery, requiring the use of bone wax. In the 2-month postoperative period, the patient presented with intraoral edema and discharge of a purulent secretion via the alveolar route. After cone beam computed tomographic images revealed increased hyperdensity inside the alveolus, alveolar curettage was performed and the material that was obtained was submitted to histopathologic examination. The results of the histopathologic analysis proved conclusive for an inflammatory foreign body reaction associated with exogenous material. A search of the PubMed, SciELO, and LILACS databases identified 22 studies that evaluated the influence of this hemostatic agent on bone healing, and an integrative review involving 367 animals and 75 humans was compiled. Bone wax is a nonresorbable material capable of negatively influencing bone healing. It is suggested that the product be used cautiously in amounts that are just enough to promote the sealing of the bone channels. [ABSTRACT FROM AUTHOR]

Chitosan is a cationic biopolymer, and its modification as a nanoparticle as well as loading a corticosteroid on it may enhance its bone regenerative effect. The aim of this study was to investigate the bone regenerative effect of nanochitosan with or without dexamethasone. Under general anesthesia, 4 cavities were created in the calvarium of 18 rabbits and filled with nanochitosan, nanochitosan with a temporally controlled release of dexamethasone (nanochitosan + dexamethasone), an autograft, or left unfilled (control). The defects were then covered with a collagen membrane. The rabbits were randomly divided into 2 groups and were sacrificed at 6 or 12 weeks after surgery. The new bone type, osteogenesis pattern, foreign body reaction, and the type and severity of the inflammatory response were evaluated histologically. The amount of new bone was determined using histomorphometry and cone-beam computed tomographic imaging. One-way analysis of variance with repeated measures was performed to compare results between the groups at each interval. A t test and chi-square test were also conducted to analyze changes in variables between the 2 intervals. Nanochitosan and the combination of nanochitosan and dexamethasone significantly increased the combination of woven and lamellar bone (P =.007). No sample showed a foreign body reaction or any acute or severe inflammation. Chronic inflammation was significantly decreased in number (P =.002) and severity (P =.003) over time. There was no significant difference between the extent and pattern of osteogenesis among the 4 groups, as evaluated by histomorphometry and cone-beam computed tomographic imaging at each interval. Nanochitosan and nanochitosan + dexamethasone were comparable with the gold standard of autograft regarding the type and severity of inflammation as well as the level and pattern of osteogenesis; yet, they induced more woven and lamellar bone. [ABSTRACT FROM AUTHOR]

Overfilling of the root canal can cause foreign body reactions and lead to pathophysiological responses. The aim of the study was to investigate the morphological properties of filling materials associated with periapical lesions through light, polarized, and fluorescent light microscopy analysis. This study reports two cases of root canal overfilling associated with unsuccessful endodontic procedures. In case #1, a 36-year-old woman complained of persistent pain in the region of tooth maxillary right first premolar, after extraction. Clinically, the patient was sensitive to any contact in the region. On radiography, a radiopaque area of 4 mm was observed in the apical region. In case #2, a 35-year-old man reported discomfort when pressing the left nostril, with a history of extraction of tooth maxillary left lateral incisor. Clinically, painless and immobile edema was observed in the overlying region. Radiographically, a radiolucent image with defined edges and a radiopaque dot within the radiolucent was visualized. In histopathology, case #1 was conclusive with foreign body granuloma, while case #2 with residual cyst. In both cases, an excisional biopsy of the lesion was performed, with complete resolution of the cases after the follow-up period. Recognizing the morphological and optical properties of endodontic lesions mixed with endodontic restorative materials is essential for an accurate and reliable histopathological report. [ABSTRACT FROM AUTHOR]

The use of implantable biomaterials to replace physiological and anatomical functions has been widely investigated in the clinic. However, the selection of biomaterials is crucial for long-term function, and the implantation of certain biomaterials can cause inflammatory and fibrotic processes, triggering a foreign body reaction that leads to loss of function and consequent need for removal. Specifically, the Wnt signaling pathway controls the healing process of the human body, and its dysregulation can result in inflammation and fibrosis, such as in peritoneal fibrosis. Here, we assessed the effects of daily oral administration of a Wnt pathway inhibitor complex (CD:LGK974) to reduce the inflammatory, fibrotic, and angiogenic processes caused by intraperitoneal implants. CD:LGK974 significantly reduced the infiltration of immune cells and release of inflammatory cytokines in the implant region compared to the control groups. Furthermore, CD:LGK974 inhibited collagen deposition and reduced the expression of pro-fibrotic α-SMA and TGF-β1, confirming fibrosis reduction. Finally, the CD:LGK974 complex decreased VEGF levels and both the number and area of blood vessels formed, suggesting decreased angiogenesis. This work introduces a potential new application of the Wnt inhibitor complex to reduce peritoneal fibrosis and the rejection of implants at the intraperitoneal site, possibly allowing for longer-term functionality of existing clinical biomaterials. [ABSTRACT FROM AUTHOR]

Nanotechnology-enabled sensors or nanosensors are emerging as promising new tools for various in-vivo life science applications such as biosensing, components of delivery systems, and probes for spatial bioimaging. However, as with a wide range of synthetic biomaterials, tissue responses have been observed depending on cell types and various nanocomponent properties. The tissue response is critical for determining the acute and long term health of the organism and the functional lifetime of the material in-vivo. While nanomaterial properties can contribute significantly to the tissue response, it may be possible to circumvent adverse reactions by formulation of the encapsulation vehicle. In this study, five formulations of poly (ethylene glycol) diacrylate (PEGDA) hydrogel-encapsulated fluorescent nanosensors were implanted into SKH-1E mice, and the inflammatory responses were tracked in order to determine the favorable design rules for hydrogel encapsulation and minimization of such responses. Hydrogels with higher crosslinking density were found to allow faster resolution of acute inflammation. Five different immunocompromised mice lines were utilized for comparison across different inflammatory cell populations and responses. Degradation products of the gels were also characterized. Finally, the importance of the tissue response in determining functional lifetime was demonstrated by measuring the time-dependent nanosensor deactivation following implantation into animal models. [ABSTRACT FROM AUTHOR]

Though the indications are quite varied, decompressive craniectomy is considered a life-saving procedure. Maximal effectiveness of craniectomy is achieved when, in addition to bone removal, the dura mater is opened properly and is augmented with duraplasty. Different synthetic materials have been used over the decades to replace the dura during decompressive craniectomy. We have used different synthetic dural replacements at our institution, including Neuro-Patch, DuraGen, and Lyoplant. In this case series, we described 4 cases that had excessive granulation tissue formation in response to a newly used synthetic dural substitute (ReDura) after emergent decompressive craniectomy. During follow-up brain imaging at different intervals, these cases were found to have foreign body reaction in the form of excessive granulation tissue formation; additionally, 1 case had a sterile pus-like collection. The granulation tissue diagnosis was affirmed by histopathology in all 4 cases. This study was an observational retrograde case series, with data obtained from electronic medical records. The study showed extensive foreign body giant cell reactions on preoperative computed tomography scans, indicating a very high occurrence rate of 72.4%, when ReDura was used as dural replacement. Our experience showed that patients are prone to develop severe foreign body giant cell reactions with ReDura. Neurosurgical centers using this material should monitor patients for possible abnormal foreign body reaction and report it to establish the safety and efficacy profile of this material. [ABSTRACT FROM AUTHOR]

Introduction • Tonsillolith, also known as tonsil stones or tonsil calculi, are the mineralization of the debris or bacteria within the crevices of the palatine tonsils. It is a rare condition with prominent symptoms of halitosis (bad breath), foreign body sensation, sore throat, painful swallowing, and cough. So far, Individualized Homoeopathy for tonsillolith has been rarely recorded in peer-reviewed journals. Methods • This case was recorded in the Medicine Department of Dr. D. Y. Patil Homoeopathic Medical College & Research Center, India. A 41-year-old male patient suffering from offensive breath and tonsil stones was treated on basis of Individualized Homeopathy medicine between 6th January 2021 and 30th May 2021. During the treatment the responses to therapy were assessed accordingly. To assess whether the changes were due to homoeopathic medicine, an assessment using Modified Naranjo Criteria was performed. Results • This case report demonstrated the treatment of tonsillolith exclusively using Individualized Homeopathy which complies the totality of the symptoms of the case over an observational period of five months. Recovery of this case helps us to strengthen the use of homoeopathy in treating rare and extensive medical cases [ABSTRACT FROM AUTHOR]

Based on the clinical and pathologic findings, she was diagnosed with cutaneous Crohn's disease of the vulva for which therapy with ustekinumab was initiated. Background A 38-year-old female diagnosed with perianal and Crohn's colitis at age 19 underwent subtotal colectomy at age 31 due to unresponsiveness of her disease to steroids, mesalamine, azathioprine, infliximab, and adalimumab. Most patients will require pharmacologic treatment; first-line therapy includes potent topical corticosteroid or topical calcineurin inhibitor (tacrolimus) with or without adjunctive antibiotic treatment. Making the Diagnosis Though vulvar lesions in Crohn's disease can be caused by a contiguous fistulizing process, the term vulvar Crohn's disease is reserved to signify a "metastatic" process, where granulomatous cutaneous lesions are separated from the affected gut by healthy tissue [[3]-[6]]. [Extracted from the article]

BACKGROUND: In recent years, the way of repairing tissue defects with biological scaffolds has been widely concerned by scholars. As an external implant, the body inflammatory response is vital for the integration between materials and tissues, in which macrophages serve as important participants and regulators. It is necessary to understand the interaction between biological scaffolds and macrophages, which will have crucial guiding significance for the design of new scaffolds in the future. OBJECTIVE: To review the researches on the interaction between biological scaffolds and macrophages as well as the regulation of this dynamic balance between them. METHODS: PubMed, Web of Science, and CNKI were used to search the related articles published from 1971 to 2021. The search terms were “macrophage polarization, M2, foreign body, tissue engineering, scaffolds, mediation, bone, degradation” in English and Chinese. An inductive analysis was conducted in the 76 selected articles on the latest research progress in this field. RESULTS AND CONCLUSION: (1) Immune response plays an indispensable role in tissue regeneration and repair. (2) Macrophage is an important regulator of inflammatory response. It will polarize into different phenotypes such as pro-inflammatory or anti-inflammatory according to different microenvironment stimuli. On one hand, the imbalance of macrophage polarization in different stages of inflammatory response will hinder the integration of biological scaffold materials and tissue repair. The high expression of pro-inflammatory macrophages in the early stage of biomaterial implantation is conducive to the integration of biomaterials. In the late stage of inflammation, however, the sustained high expression of pro-inflammatory macrophages will hinder the formation of new bone. On the other hand, the properties of biological scaffolds (composition, hardness, roughness, surface geometry, hydrophilicity, etc.) will affect the polarization direction of macrophages. For example, adjusting the surface morphology of scaffolds cannot change the ideal physical and chemical properties of scaffolds, but promote effectively the polarization of macrophages towards pro-regenerative phenotype and tissue repair. (3) At present, the effect of biological scaffolds on macrophages has been realized by changing the composition, preparation methods and adjusting the physical and chemical properties of scaffolds. However, how to efficiently regulate this dynamic balance is still the focus and our key direction in the future, In particular, how to successfully translate the ideal results of basic research in vitro into practical application in vivo is still under further exploration. [ABSTRACT FROM AUTHOR]

Simple Summary: A 3D scaffold developed for inguinal hernia repair has been designed to overcome the multiple incongruences of currently used flat meshes. Conventional hernia implants, positioned in a high-motile environment, are static, need fixation and, instead of healing the degenerative source of hernia disease, produce a granuloma of low-quality scar tissue. On the contrary, the new 3D scaffold, endowed with centrifugal expansion, avoids fixation, reacts dynamically to the motile impulses of the groin and attracts tissue growth factors, promoting the development of newly formed tissue structures. Despite being made of the same polypropylene material as conventional flat meshes, the dynamic behavior of the 3D scaffold that moves in tune with inguinal movements proves that modifying the design and kinetic attitude turns the biological response into tissue regeneration. Surgical repair of groin protrusions is one of the most frequently performed procedures. Currently, open or laparoscopic repair of inguinal hernias with flat meshes deployed over the hernial defect is considered the gold standard. However, fixation of the implant, poor quality biologic response to meshes and defective management of the defect represent sources of continuous debates. To overcome these issues, a different treatment concept has recently been proposed. It is based on a 3D scaffold named ProFlor, a flower shaped multilamellar device compressible on all planes. This 3D device is introduced into the hernial opening and, thanks to its inherent centrifugal expansion, permanently obliterates the defect in fixation-free fashion. While being made of the same polypropylene material as conventional hernia implants, the 3D design of ProFlor confers a proprietary dynamic responsivity, which unlike the foreign body reaction of flat/static meshes, promotes a true regenerative response. A long series of scientific evidence confirms that, moving in compliance with the physiologic cyclical load of the groin, ProFlor attracts tissue growth factors inducing the development of newly formed muscular, vascular and nervous structures, thus re-establishing the inguinal barrier formerly wasted by hernia disease. The development up to complete maturation of these highly specialized tissue elements was followed thanks to biopsies excised from ProFlor from the short-term up to years post implantation. Immunohistochemistry made it possible to document the concurrence of specific growth factors in the regenerative phenomena. The results achieved with ProFlor likely demonstrate that modifying the two-dimensional design of hernia meshes into a 3D outline and arranging the device to respond to kinetic stresses turns a conventional regressive foreign body response into advanced probiotic tissue regeneration. [ABSTRACT FROM AUTHOR]

BACKGROUND Nasal silicone injections have been a common procedure among Asians. However, this procedure can lead to severe complications. Unfortunately, there are limited data available on the distortive characteristics of nasal siliconoma in the Asian population. This study aimed to provide objective data on the distortive characteristics of nasal siliconoma to be a reference for a treatment outcome. METHODS This cross-sectional study was conducted at Cipto Mangunkusumo Hospital from June 2017 to March 2018 involving 30 Asian females with nasal siliconoma. Nasal photogrammetric measurements were taken using a portable mirror stand device and analyzed to formulate the distortive characteristics. RESULTS The mean (standard deviation) of intercanthal width was 3.33 (0.25) cm, nasal root width was 2.70 (0.30) cm, alar width was 4.48 (0.31) cm, two tip-defining points (TDP) distance was 2.09 (0.22) cm, nasofrontal angle was 141.10 (8.40)°, length of the nose was 3.10 (0.48) cm, nasofacial angle was 32.94 (4.51)°, nasion projection was 0.64 (0.36) cm, pronasion projection was 2.00 (0.25-2.46) cm, tip angle was 122.7 (4.52)°, nasolabial angle was 78.81 (15.93)°, columella length (n = 20) was 0.64 (0.20) cm, tip lobular portion length was 1.12 (0.20) cm, the extend of extended columella was 0.47 (0.31) cm, and base of the nasal width was 3.98 (0.25) cm. CONCLUSIONS Nasal siliconoma in Asians had certain characteristics such as a wider nasal root, wider two TDP distance, wider nasion projection, acute nasolabial angle, hanging columella, and a long lobular portion of the tip. [ABSTRACT FROM AUTHOR]

Background: Sacrococcygeal pilonidal disease is an infection of the skin and subcutaneous tissue at or near the upper part of the natal cleft of the buttocks. This results from the chronic infection of hair follicles and the subsequent formation of a subcutaneous abscess. Hair then enters the abscess cavity and provokes a foreign body tissue reaction with chronic suppuration and discharge. The aim of this study was to select the best method of treatment for pilonidal sinus. Methods: This randomized controlled trial was conducted on 56 patients with the diagnosis of pilonidal sinus disease who were admitted to the Department of General Surgery, Zagazig University Hospitals, from March 2020 to September 2020. The patients were allocated randomly into four groups, each including 14 patients. Group (1): This was the conservative approach, which included medical treatment and drainage if necessary. The open technique was used in Group (2). Group (3): were operated by the Limberg flap technique. Group (4): were operated by Karydakis's technique. All patients were subjected to a history, a complete clinical examination, and preoperative laboratory investigations. Results: Recurrence was significantly associated with open and conservative groups, while there was only one case in the Limberg group and no case in the Karydakis group. Conclusions: The Karydakis flap procedure should be chosen instead of the Limberg flap for treating uncomplicated sacrococcygeal pilonidal disease because of its shorter operative time, earlier return to work, faster healing time, and significantly higher patient satisfaction. [ABSTRACT FROM AUTHOR]