Fibrous Tissue Capsule Research Articles

Problems of diagnosis and treatment of echinococcosis

The lack of specificity of clinical and laboratory manifestations of echinococcosis allocates to the fore diagnostic tool methods of research, which are at present leading in identifying the disease. The widespread introduction into clinical practice of modern highly informative instrumental methods such as ultrasonography (US) and computed tomography (CT), significantly improved the early detection of liver echinococcosis. In conjunction with the serological reactions to echinococcosis they allow in most cases the diagnosis of the disease. However, false-negative results of serological tests in more than 10–20 % of the patients and the difficulty of differential diagnosis with small brush size and pseudotumoral forms of ultrasound often lead to delayed diagnosis, and thus to a deterioration of treatment results. Moreover, failure to identify at an early stage of echinococcosis virtually eliminates the possibility of conservative treatment of echinococcosis without performing surgery. It is given the profound immune disorders in patients with echinococcosis, treatment should be complex and along with the surgical removal of hydatid cyst should be included in it and biostimulating. Immunocorrecting lechebnye event. Recent require further development. Methods. The work is based on an analysis of 25 cases operated on echinococcosis in the period from January 2013 to December 2014. To confirm the diagnosis using tools (ultrasound, computed tomography, X-ray), serology (detection of antibodies to echinococcus ELISA), histological (after removal of cysts) methods. The data are processed by the method of variation statistics. Results. An analysis of 25 cases of echinococcosis showed that among the 15 cases dominated by women (60 %) versus 10 (40 %) men. Treatment – removal of cysts of 25 patients with echinococcosis is made surgically. Among the analyzed cases in 6 (20.4 %) patients had the relapsing form of the disease. The factors leading to relapse of the disease are saved in the patient's body small residual cyst, inaccessible modern instrumental methods of diagnosis; preservation of fibrous tissue capsule and pericystic embedded germ cells that can transform into the cyst; seeding germ elements during the operation. Relapses of the disease usually associated with the colonization of the abdominal cavity with the cysts rupture, incomplete removal of the child bubbles, technical errors in surgery. Therefore, one of the most pressing issues is the chemoprophylaxis echinococcosis recurrence after surgical treatment. Conclusion. The difficulties caused by polymorphism of clinical diagnosis of symptoms and the lack of adequate diagnosis. Frequent recurrence of echinococcosis (20.4 %) after surgery indicates the need for preventive treatment of disease

Sinu-Atrial Node of Mature Dromedary Camel Heart (Camelus dromedarius) with Special Emphasis on the Atrial Purkinje Like Cardiomyocytes

The sinu-atrial node (SAN) is one of the impulse conducting system of the camel heart. Anatomically, it lies beneath the epicardium, at the cranial end of the terminal sulcus, near the junction between the superior vena cava to the lateral wall of the right atrium and the right auricle. Histologically, SAN is located in the subepicardial layer of the terminal crest and can be identified as a mass of specialized and modified cardiac myocytes. Moreover, it appeared elongated in shape and bent oblong. SAN appears strongly similar to the general structure of the glands where, it is formed of two parts; the stroma and the parenchyma. The stroma is consisted of a fibrous connective tissue capsule that is completely investing the SAN from all sides. From the capsule, thin connective tissue septa or trabeculae are extending to inside the node, dividing the later into lobes. These lobes form the SAN head or the SAN body. From this body, the SAN arms processes take their way out. These arms are considered the internodal and interatrial pathways to the different sites in the right and left atria. So, the SAN head with arms giving the octopus like-appearance for the node. The parenchyma is consisted of three different types of specialized and modified cardiac myocytes; the perinuclear clear zone cells (“P” cells), the transitional cells (“T” cells) and the atrial Purkinje like cells or Purkinje like conducting cells.

Sinu-atrial Node of Mature Dromedary Camel Heart (Camelus dromedarius)with special Emphasis on the Atrial Purkinje like Cardiomyocytes

The sinu-atrial node (SAN) is one of the impulse conducting system of the camel heart. Anatomically, it lies beneath the epicardium, at the cranial end of the terminal sulcus, near the junction between the superior vena cava to the lateral wall of the right atrium and the right auricle. Histologically, SAN is located in the subepicardial layer of the terminal crest and can be identified as a mass of specialized and modified cardiac myocytes. Moreover, it appeared elongated in shape and bent oblong. SAN appears strongly similar to the general structure of the glands where, it is formed of two parts; the stroma and the parenchyma. The stroma is consisted of a fibrous connective tissue capsule that is completely investing the SAN from all sides. From the capsule, thin connective tissue septa or trabeculae are extending to inside the node, dividing the later into lobes. These lobes form the SAN head or the SAN body. From this body, the SAN arms processes take their way out. These arms are considered the internodal and interatrial pathways to the different sites in the right and left atria. So, the SAN head with arms giving the octopus likeappearance for the node. The parenchyma is consisted of three different types of specialized and modified cardiac myocytes; the perinuclear clear zone cells (“P” cells), the transitional cells (“T” cells) and the atrial Purkinje like cells or Purkinje like conducting cells.

A Comparative Study of the Dentition and Temporomandibular Joint Anatomy and Histology Adult Dogs

Purpose: To describe and evaluate normal adult dog dentition and temporomandibular joint anatomically and histologically in comparison to humans. Method: Five adult dogs (6-12 months old) were used in this study. The following anatomical structures were histologically evaluated in a qualitative fashion: Teeth and related bony structures mandible, mandibular condyle, disc, Zygomatic arch, temporal bone, glenoid fossa, retrodiscal tissue and synovia. The macroscopical and microscopic study of the human TMJ was based on the current literature. Results: Dogs have three Incisors, one canine, four premolars, and 2 molars in the upper and 3 molars in the lower jaw. The TMJ is surrounded by a thin fibrous tissue capsule, and a synovial lining. The mandibular angle has a prominent shape. The glenoid fossa is flat, with extended mediolaterally with retroarticular process. Histologically, the TMJ is composed of different tissues that comprise the mandibular head, mandibular fossa and fibrocartilaginous disc. A layer of fibrous tissue covers the articulating cortical condyle and temporal bone followed by a layer of hyaline cartilage. Conclusion: Morphologically and numerically dog's teeth are different from humans. Morphologically and histologically, the articular structure of dogs is, on the whole, similar to that of humans. In these animals there is no articular eminence, but they have a retroarticular process.

A correlation of computed tomography perfusion and histopathology in tumor edges of hepatocellular carcinoma

The peripheral morphologic characteristics of hepatocellular carcinoma (HCC) reflect tumor growth patterns. Computed tomography (CT) perfusion is a new method to analyze hemodynamic changes in tissues. We assessed the relationship between CT perfusion and histopathologic findings in the periphery of HCC lesions. Non-contrast CT, enhanced dual-phase CT, and CT perfusion were performed on 77 subjects (47 patients and 30 controls). Based on the imaging findings of enhanced dual-phase CT, the tumor edges were classified into three types: type I (sharp); type II (blurry); and type III (mixed). The CT perfusion parameters included hepatic blood flow, hepatic arterial fraction, hepatic arterial perfusion, and hepatic portal perfusion. The tissue sections from resected specimens were subjected to routine hematoxylin and eosin staining and immunohistochemical staining for CD34. The correlations between microvessel density (MVD) and the CT perfusion parameters were analyzed using Pearson's product-moment correlation coefficient. Changes in the perfusion parameters in tumor edges of different tumor types were evaluated. Type I (sharp): the pathologic findings showed fibrous connective tissue capsules in the tumor edges, and an MVD ≤30/mm2. Type II (blurry): the histology showed that the edges were clear with no capsules and an MVD>30/mm2. Type III (mixed): the pathology was similar to that of types I and II, and an MVD>30/mm2. Hepatic blood flow, hepatic arterial fraction, hepatic arterial perfusion, and hepatic portal perfusion were significantly increased in the tumor edges of HCC patients compared to those of the controls (P<0.05). The correlation between CT perfusion parameters and MVD was higher in blurry tumor edges of type II than in those of types I or III. CT perfusion imaging of tumor edges may be helpful in revealing histopathological features, and indirectly reflect angiogenic changes of HCCs.

Sialolipoma of Minor Salivary Glands: Presentation of Five Cases and Review of the Literature with an Epidemiological Analyze

Sialolipoma is rare benign neoplasm arise from salivary glands (majors and minors) characterized by neoplastic adipose tissue with scattered non-neoplastic salivary gland acinus. To date 60 cases (including 5 cases reported in the present paper) have been reported in scientific literature. This article presents 5 new cases of sialolipoma affecting minor salivary glands (MiSG) and additionally reviews and analyzes the previously published cases to assess possible demographical differences between sialolipoma from minor and from major salivary glands. 5 cases (3 females; 2 males; age means 63.8years), of sialolipoma from MiSG, are reported. 2 of them were located in buccal mucosa, 1 in upper lip mucosa, 1 in floor of the mouth and 1 in retromolar area. All tumors were composed by neoplastic adipocytes cells interlaced with normal salivary gland acinus cover it by a fibrous tissue capsule. Analyzes of literature showed that MiSG sialolipoma is most frequent in females over 60years old, therefore and in conclusion this article assess different demographical profile of sialolipoma in respect to their topography.

Cistos epidermais em ovinos

São descritos os aspectos clínico-patológicos de cistos epidermais em quatro ovinos, com idade entre dois e 12 anos, oriundos da região central do Rio Grande do Sul, Brasil. Três desses ovinos apresentavam múltiplos nódulos cutâneos, distribuídos aleatoriamente pelo corpo, e um ovino apresentava nódulo cutâneo solitário na região cervical. O período entre o aparecimento do primeiro nódulo e o surgimento de múltiplos nódulos foi de oito meses, em um caso, e um ano, em dois casos. Os quatro ovinos eram os únicos animais afetados em seus respectivos rebanhos. Os nódulos cutâneos eram redondos ou ovais, salientes, flutuantes, não pruriginosos e recobertos por pele parcialmente alopécica. Esses nódulos variavam de 1,0 a 7,0cm de diâmetro e, ocasionalmente, apresentavam um pequeno orifício central, com 1-2mm de diâmetro, na superfície externa. Ao corte eram císticos, delimitados por uma parede fina e branca, com 0,5-0,8cm de espessura, e preenchidos por material branco ou amarelado e friável. Histologicamente, os cistos eram revestidos por epitélio, contendo todos os estratos de um epitélio escamosos estratificado, sobre uma fina cápsula de tecido conjuntivo fibroso denso. Os cistos eram preenchidos por agregados homogêneos e feixes de ceratina, arranjados de forma concêntrica. Baseado na localização e características macroscópicas e histológicas esses cistos foram diagnosticados como cistos epidermais infundibulares.

Degradability and cytocompatibility of tricalcium phosphate/poly(amino acid) composite as bone tissue implants in orthopaedic surgery

In this study, a tricalcium phosphate (TCP) and poly (amino acid) copolymer (PAA) biocomposite were fabricated for bone repair and characterized. The results show that the compressive strength of the TCP/PAA composites increased with an increase in the TCP content at TCP contents less than 40 w%. The weight loss of the composite after soaking in phosphate buffered saline for 12 weeks significantly increased with an increase in the TCP content, revealing its good degradability. In addition, the composite maintained adequate mechanical strength during the degradation period because it underwent a surface erosion process. In vitro MG63 cell culture experiments showed that the composite is non-cytotoxic and thus allows cells to adhere, proliferate and differentiate. Osteoid formation was evidenced on the composite surfaces 12 weeks after its implantation into the femoral bone of dogs. Furthermore, the composite combined directly with the host bone tissue without fibrous capsule tissue, and no inflammatory responses were found, showing the good biocompatibility of the composite. It is expected that the composite may be used for the development of bone implants for orthopaedic surgery.

Glandular Odontogenic Cyst: Case Report

Glandular odontogenic cyst is an aggressive, uncommon cyst that appears clinically as slowly increasing swelling that is asymptomatic in middle-aged adults. Woman, 73, complained of pain between the roots of left mandibular canines and premolars. Intraoral examination revealed swelling with fluctuation on palpation. Radiographically, a well-defined unilocular radiolucent area was noticed. Preoperative fine needle aspiration was performed. The clinical diagnosis of lateral periodontal cyst was suggested, prompting an incisional biopsy. Microscopically, the specimen was characterized by a capsule of fibrous connective tissue lined by cubic to columnar epithelium with mucous and ciliated cells. The definitive diagnosis was glandular odontogenic cyst. The patient was referred to surgery for complete removal of the lesion. Because of this lesion's aggressive behavior the patient will be followed periodically.

Processing, characterization and biological testing of electrochemically modified titanium for dental implants

Biomedical applications of titanium and its alloys are possible due to their suitable characteristics for bone replacement, including good mechanical properties, excellent corrosion resistance and high biocompatibility. However, one of their main limitations is the fibrous tissue capsule that is formed around the material, which can be related with implants loosening. As an alternative to solve this problem, in this work were carried out some chemical and electrochemical modifications of titanium surface, in order to evaluate their influence on implants osteointegration through in vitro testing in contact with osteoblasts. Results of scanning electron microscopy (SEM), roughness parameters measured and osteoblasts morphology indicate that there is a relationship between surface roughness and bone cells adhesion. Surfaces with highest vertical roughness parameters, within evaluated conditions, allowed better cells adhesion. These results suggest that a combination of chemical and electrochemical techniques can help to control surface roughness of titanium dental implants and, by this way, it can also allow to optimize osteointegration.

Development of a bioactive composite of nano fluorapatite and poly(butylene succinate) for bone tissue regeneration.

The development of a bioactive nanocomposite for bone replacement has gained much interest in the field of bone grafting. In this study, a nano fluorapatite (n-FA)-poly(butylene succinate) (PBS) bioactive composite was fabricated using a co-solution method. The results showed that the n-FA-PBS composite had improved hydrophilicity, compressive strength and an elastic modulus, which were obviously higher than those of PBS alone. In addition, the n-FA-PBS composite could inhibit bacterial attachment, with the number of viable bacteria on the composite obviously lower than on pure PBS, indicating good antibacterial ability. Moreover, the attachment and proliferation of human mesenchymal stem cells (hMSCs) on the n-FA-PBS composite was significantly higher than on PBS, and the alkaline phosphatase (ALP) activity of hMSCs on the composite was expressed at significantly higher levels compared to PBS. Furthermore, the hMSCs showed intimate contact with the composite surface and the cells spread and grew significantly better on the composite compared to PBS. Therefore, incorporation of n-FA into PBS is a good way to prepare an inorganic-organic bioactive composite of a nano ceramic and a polymer, which supports cell attachment, proliferation and differentiation. The implantation of the n-FA-PBS composite into the femoral bone of rabbits confirmed that the new bone tissue could form on the composite surfaces, and the composite combined directly with the natural bone tissue without fibrous capsule tissue, showing good osteoconductivity. In short, the n-FA-PBS bioactive composite has good biocompatibility and bioactivity, and has potential application in bone regeneration.

Canalicular adenoma of the parotid gland: A case report

Canalicular adenomas are uncommon benign salivary gland tumors commonly affecting the minor salivary glands. Usually, 90-95% of these are reported to occur in the upper lip, followed by the buccal mucosa and palate. Here, we report a case that involved the major salivary gland as a solitary discrete mass in the lower pole of the parotid gland. The mass was surgically excised and which histopathologically revealed normal parotid tissue along an extremely cellular area enveloped by a fibrous connective tissue capsule. Cellular areas showed cells with hyperchromatic nuclei, basally placed nucleus arranged in the form of interlacing cords, small islands, all separated by thin delicate connective septa all these features characteristic of canalicular adenoma.

Tissue reaction induced by implanted venous access ports in adult patients after infection of the implantation site

Implantable long-term central venous port systems (CVPS) are widely used as a permanent means of accessing the vascular system for intravenous delivery of drugs, parenteral nutrition, blood transfusion, and blood sampling. These systems allow easy and repetitive puncture without causing much damage to the vessels. However, the body foreign surface of CVPS induces an inflammatory response with varying intensity (depending on the implant materials) that leads to formation of a fibrous tissue capsule around the implant. This study was designed to investigate the influence of bacterial infection on the tissue reaction induced by implanted CVPS in adult patients. 20 patients (9 women, 11 men, 58 ± 14 yrs of age) were included in this study. These patients received explantation of a polysulfone based CVPS (ChemoSite™, Covidien, Mansfield, USA) due to port related infections (patients with bacterial infections at the implantation site: group A, 5 men, 1 women) or to other reasons such as termination of treatment, thrombosis, or CVPS dysfunction (patients without bacterial infections, group B, 6 men, 8 women) 299.9 ± 261.2 days after CVPS implantation. A sample of the encapsulating tissue covering the CVPS together with surrounding tissue (at least 1 × 1 cm2) was placed in a small container with fixing agent, a buffered neutral 4% formalin solution (pH 7). Histological sections of the samples were prepared for light microscopic analysis after paraffin embedding. Sections of 3 μm were cut and stained with haematoxylin and eosin, Weigert's elastic stain, and Heidenhain's azan stain. There was no difference in thickness, collagen and elastin content, or cell and capillary density of the fibrous capsule between both groups. Due to the wound healing reaction involving angiogenesis and fibroblast activation cell density and number of capillaries in the capsule tissue of all patients showed a positive correlation (r = 0.45, p < 0.05). However, the study demonstrated that at the end of the foreign body reaction the artificial tissue layer which covers the CVPS after implantation due to foreign body reaction shows only low reactivity towards infections.

Incidental &lt;i&gt;Mycobacterium&lt;/i&gt;-induced granulomatous inflammation of the follicular pharyngeal tonsils in a South African farmed ostrich (&lt;i&gt;Struthio camelus&lt;/i&gt;)

Avian mycobacteriosis (AM) is a zoonotic disease caused by Mycobacterium aviumcomplex (MAC), which can spread from avians to other farmed animals such as cattle and pigs as well as to humans. This study is the first report of granulomatous inflammation, as a result of avian mycobacteriosis, in the follicular pharyngeal tonsils of a farmed ostrich. The head of an apparently healthy farmed adult ostrich was obtained after slaughter. Each pharyngeal fold displayed a large tissue mass. This tissue was routinely prepared for light microscopy and stained with haematoxylin and eosin, periodic acid Schiff, Grocott methenamine silver, Gram and Ziehl-Neelsen. Immunohistochemistry (IHC) and polymerase chain reaction (PCR) were performed to identify Mycobacterium spp. and Mycobacterium tuberculosis complex, respectively. Histologically, the tissue masses consisted of confluent mature micro-granulomata that were characterised by central caseous necrosis surrounded by multinucleated giant cells, macrophages and lymphoid cells and an outer mature fibrous connective tissue capsule. Within some foci of caseous necrosis were variably sized colonies of small, Gram-negative, acid-fast bacilli, which showed positive IHC labelling for Mycobacterium spp., leading to a presumptive diagnosis of AM. PCR thus proved useful in excluding the presence of notifiable Mycobacteriumspp. The significance and role of the pharyngeal tonsils of ratites in diseases such as AM warrant specific attention. Moreover, as ratites are known to present with AM infections with apparently no visible loss in body condition, as presumably occurred in the present case, it is imperative that unusual masses in apparently healthy ratites be thoroughly investigated.

Evaluation of oral tissue response and blood levels of mercury released from dental amalgam in rats

Dental amalgam is the most common restorative material used in dentistry. It was reported that amalgam might constitute potential toxic hazards to pregnant patients and foetuses through mercury release and absorption. The present study aimed to investigate the vital tissue response in contact to dental amalgam plus determination of blood mercury levels in mother and offspring Wistar strain albino rats. Pregnant mothers were divided into two main groups each had dental amalgam implanted into either an oral mucosa incision or a bony socket following extraction. Third and fourth groups included the offspring rats of mothers from the first and second groups, respectively. The blood mercury levels and histopathology of oral tissues were analyzed in mothers at one and six months post-implantation and in offspring rats one day after birth. The blood mercury levels of mothers increased significantly at six months (P<0.01) as compared to levels at one month. However, blood mercury levels were not significant (P>0.05) when the two offspring (third and fourth) groups were compared. Histopathology results from mothers showed inflammatory response at the bottom of the socket, one month after amalgam implantation. At six months, teeth germs showed vacuolation of the abnormal odontoblasts with globular dentine formation. Degenerated periodontal fibres and thin trabeculae forming the bony sockets with large marrow spaces were evident. A fibrous connective tissue capsule surrounded the amalgam mass inside the mucosa of mothers at one month and was evident also at 6 months with a huge inflammatory cell infiltrate. Teeth germs showed elongated odontoblasts with intercellular oedema, thinner dentine and bony trabeculae with wider marrow spaces. Offspring rats showed comparable oral tissue response. ConclusionsThere is a positive correlation between blood mercury levels and oral tissue response in mothers, however, the negative impact of mercury on oral tissues of offspring rats was due to high mercury levels in their mothers’ blood during pregnancy. We would recommend that women should – as far as possible – postpone having dental amalgam filling placed or removed during pregnancy to avoid its harmful effect on the foetus. Further clinical studies are recommended to test our findings in man.

Response of mice connective tissue to three different endodontic materials

The aim of this study was to evaluate the biocompatibility of mineral trioxide aggregate (MTA) Bio and Portland cement (PC) and compare with those of ProRoot MTA. Polyethylene tubes were filled with materials and placed into dorsal subcutaneous connective tissue of Wistar albino rats. After 7, 30, and 60 days after the surgical procedure, the implants with the surrounding tissue were removed. Tissue samples were subjected to histological processing, and sections were stained with hematoxylin and eosin. Sections were evaluated for the intensity of inflammation, predominant cell type, presence of fibrous capsule and granulation tissue. Data were submitted to Kruskal-Wallis test at a significant level of P ≤ 0.05. No statistical differences were observed at any evaluated condition among tested materials (P > 0.05). Statistically significant differences were observed between mean inflammatory scores, cell types and granulation tissue of the same material in different experimental periods (P < 0.05). Can be concluded that biocompatibility of MTA bio and PC were comparable with that of ProRoot MTA.

Coating of carbon fiber‐reinforced polyetheretherketone implants with titanium to improve bone apposition

Carbon fiber-reinforced polyetheretherketone (CF/PEEK) is a thermoplastic composite biomaterial exhibiting properties suitable for load-bearing orthopedic implants. However, the hydrophobic surface of CF/PEEK implants induces the deposition of a peri-implant fibrous tissue capsule preventing bone apposition. However, if bone apposition was improved, the use of CF/PEEK in orthopedics could be increased as it has many advantages compared with metallic implants. In this study, CF/PEEK screws were coated with titanium (Ti) using two different techniques, namely vacuum plasma spraying (VPS) and physical vapor deposition (PVD) with uncoated screws as controls. These coatings were characterized and implanted in a loaded sheep tibia model. In the characterization of the screw surfaces using microscopy techniques, the uncoated screws were seen to have an irregular surface. The PVD coating appeared smooth and consistent, whereas the VPS coating appeared to be a rough coating with some inhomogeneities, which did not cover the entire surface area. Nevertheless, in the ex vivo analysis the VPS-coated screws had a screw removal torque which was statistically greater than uncoated and PVD-coated screws (p ≤ 0.002 for both comparisons). Additionally, the VPS-coated screws had a statistically higher bone contact area than the uncoated screws (p = 0.006), whereas no statistical difference was detected between VPS and PVD coating types (p = 0.11). Thereby illustrating that Ti coating of CF/PEEK screws significantly improve bone apposition and removal torque compared with uncoated CF/PEEK screws.

Platelet‐rich plasma‐derived growth factors promote osteogenic differentiation of rat muscle satellite cells: in vitro and in vivo studies

PRP (platelet-rich plasma)-derived growth factors are a new application of tissue engineering and a developing area for researchers and clinicians. We have assessed the effects of PRP-derived growth factors on the proliferation and osteogenic differentiation of rMSCs (rat muscle satellite cells), and constructed a novel tissue engineering bone composed of PRP-derived growth factors and rMSCs. PRP were created by a freeze-thaw process. rMSCs were isolated from rat masticatory muscle using serial platings technique. Wst-1 assay, SEM (scanning electron microscopy), ALP (alkaline phosphatase) activity, total protein concentration, AR (Alizarin red S) staining, calcium analyses and RT-PCR (reverse transcription-PCR) of osteogenic-related genes were used to assess the effect of PRP-derived growth factors on proliferation and osteogenic differentiation of cultured rMSCs on scaffolds. The different composite scaffolds were implanted to the subcutaneous spaces of nude mice. H&E (haematoxylin and eosin) and Masson's trichrome staining were used to examine the ectopic bone formation. In vitro, we found that PRP-derived growth factors showed excellent cell compatibility and significantly enhanced cell proliferation over serum and control groups at 48 and 72 h. SEM, ALP activity, AR staining, calcium analyses and RT-PCR showed that PRP-derived growth factors significantly increased cells osteogenic differentiation when compared with other groups. In vivo examination showed that more fibrous tissue capsule and bone with lamellar structures appeared in PRP-derived growth factors groups. These results suggest that the PRP-derived growth factors significantly promote rMSCs proliferation, osteogenic differentiation compared with serum and scaffolds alone, and may be suitable for stem cell growth factors delivery and bone tissue engineering.

Theoretical study of the fibrous capsule tissue growth around a disk-shaped implant

We analyze the mathematical properties of the fibrous capsule tissue concentration around a disk-shaped implant. We establish stability estimates as well as monotonicity results that illustrate the sensitivity of this growth to the biocompatibility index parameters of the implant. In addition, we prove that the growth of the tissue increases exponentially in time toward an asymptotic regime. We also study the mathematical properties of the solution of the inverse problem consisting in the determination of the values of the biocompatibility index parameters from the knowledge of some fibrous capsule tissue measurements. We prove that this model calibration problem admits a unique solution, and establish a characterization of the index parameters. Furthermore, we demonstrate analytically that such a solution is not continuous with respect to the data, and therefore the considered inverse problem is ill-posed due to the lack of the stability requirement.

Increased connective tissue attachment to silicone implants by a water vapor plasma treatment

Polydimethylsiloxane (PDMS) is the most common type of silicone polymer for the fabrication of implantable medical devices. Because of its inherent hydrophobic nature, the PDMS surface does not readily promote cellular adhesion, which leads to diverse clinical issues. Previously, we reported a simple water vapor plasma treatment of PDMS surfaces that resulted in stable long-term wettability and excellent in vitro cell compatibility. In this work, we report investigation of the in vivo local responses to PDMS implants treated by water vapor plasma using a subcutaneous rat model. The local tissue responses were assessed after 2 and 4 weeks of implantation by means of macroscopic and histomorphometric analysis. After 2 weeks of implantation, the plasma-treated implants elicited the formation of fibrous tissue capsules that were significantly thinner, more adherent, and vascularized than the control counterparts. The improved cell adhesion was correlated with an increased amount of cells attached to the implant surface after retrieval. There was no difference in the inflammatory response between untreated and treated samples. This study provides a rational approach to optimize the long-term performance of silicone implants, which is likely to have a significant impact in clinical applications demanding enhanced tissue integration of the implants.