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2-Methoxy-1,4-Naphthoquinone (MNQ) suppresses the invasion and migration of a human metastatic breast cancer cell line (MDA-MB-231)

Liew K, Yong PV, Lim YM, Navaratnam V, Ho AS

Toxicol In Vitro, 2014 Apr;28(3):335-9.
PMID: 24291160 DOI: 10.1016/j.tiv.2013.11.008

Metastasis contributes to the escalating mortality rate among cancer patients worldwide. The search for novel and more effective anti-metastatic agent is crucial owing to the lack of anticancer drugs that can successfully combat metastasis. Hence, this study aims to examine the effects of 2-Methoxy-1,4-Naphthoquinone (MNQ) towards the metastasis of MDA-MB-231 cells. In invasion assays, the number of cells permeating across a Matrigel barrier was found to be decreased in a dose-dependent manner upon treatment with MNQ (0-7.5 μM). In wound-healing migration assays, MNQ exhibited dose-dependent inhibition of cell migration in which significant reduction in the zone of closure was observed as compared to untreated controls. Furthermore, the proteolytic activity of a pivotal metastatic mediator, matrix metalloproteinase-9 (MMP-9) was also downregulated by MNQ as determined by gelatin zymography. This study reports for the first time, the ability of MNQ to inhibit the invasion and migration characteristics of a highly metastatic MDA-MB-231 cancer cell line.

Matched MeSH terms: Collagen/metabolism
Fulltext A Rare Case of Spinal Extradural Arachnoid Cyst with Cord Compression

Lin LC, Jason R

Asian J Neurosurg, 2018 4 24;13(2):468-470.
PMID: 29682063 DOI: 10.4103/ajns.AJNS_310_16

Spinal extradural arachnoid cysts are rare lesions which typically involve the thoracic spine and are an asymptomatic condition of unknown origin. They may also produce symptoms by compressing the spinal cord or nerve roots. Surgery is the treatment of choice in such lesions, but asymptomatic patients can be managed conservatively. We present a case of symptomatic, probable traumatic origin, spinal arachnoid cyst at our center in Hospital Kuala Lumpur, Malaysia. Magnetic resonance imaging spine showed well-defined, nonenhancing extradural cystic lesion from T5 to T6 vertebrae level compressing spinal cord anteriorly. The patient underwent T5, T6 laminoplasty, T4 partial laminectomy and excision of the cyst. Histologically, the cyst wall comprised of collagen and meningothelial cells. This surgical intervention achieved neurological improvement in terms of motor power in our follow-up of this patient.

Matched MeSH terms: Collagen
Fulltext A case of prolonged fever and a diagnosis obscured by an opaque sinus

Velayudhan M, Lee CW

Med J Malaysia, 2014 Jun;69(3):140-1.
PMID: 25326357 MyJurnal

Prolonged fever in patients can be a diagnostic challenge. Clinicians generally consider infectious diseases, malignant diseases and collagen vascular diseases as possible causes of pyrexia of unknown origin (PUO). Even after extensive evaluation as many as 15 percent of patients with prolonged fever may remain undiagnosed. This case report describes subacute thyroiditis as a cause of prolonged fever and documents how that diagnosis was finally made after 40 days of fever.

Matched MeSH terms: Collagen
A comparative study of skin cell activities in collagen and fibrin constructs

Law JX, Musa F, Ruszymah BH, El Haj AJ, Yang Y

Med Eng Phys, 2016 Sep;38(9):854-61.
PMID: 27349492 DOI: 10.1016/j.medengphy.2016.05.017

Collagen and fibrin are widely used in tissue engineering due to their excellent biocompatibility and bioactivities that support in vivo tissue formation. These two hydrogels naturally present in different wound healing stages with different regulatory effects on cells, and both of them are mechanically weak in the reconstructed hydrogels. We conducted a comparative study by the growth of rat dermal fibroblasts or dermal fibroblasts and epidermal keratinocytes together in collagen and fibrin constructs respectively with and without the reinforcement of electrospun poly(lactic acid) nanofiber mesh. Cell proliferation, gel contraction and elastic modulus of the constructs were measured on the same gels at multiple time points during the 22 day culturing period using multiple non-destructive techniques. The results demonstrated considerably different cellular activities within the two types of constructs. Co-culturing keratinocytes with fibroblasts in the collagen constructs reduced the fibroblast proliferation, collagen contraction and mechanical strength at late culture point regardless of the presence of nanofibers. Co-culturing keratinocytes with fibroblasts in the fibrin constructs promoted fibroblast proliferation but exerted no influence on fibrin contraction and mechanical strength. The presence of nanofibers in the collagen and fibrin constructs played a favorable role on the fibroblast proliferation when keratinocytes were absent. Thus, this study exhibited new evidence of the strong cross-talk between keratinocytes and fibroblasts, which can be used to control fibroblast proliferation and construct contraction. This cross-talk activity is extracellular matrix-dependent in terms of the fibrous network morphology, density and strength.

Matched MeSH terms: Collagen
Fulltext A comparative study on in vitro osteogenic priming potential of electron spun scaffold PLLA/HA/Col, PLLA/HA, and PLLA/Col for tissue engineering application

Balaji Raghavendran HR, Puvaneswary S, Talebian S, Murali MR, Raman Murali M, Naveen SV, et al.

PLoS One, 2014;9(8):e104389.
PMID: 25140798 DOI: 10.1371/journal.pone.0104389

A comparative study on the in vitro osteogenic potential of electrospun poly-L-lactide/hydroxyapatite/collagen (PLLA/HA/Col, PLLA/HA, and PLLA/Col) scaffolds was conducted. The morphology, chemical composition, and surface roughness of the fibrous scaffolds were examined. Furthermore, cell attachment, distribution, morphology, mineralization, extracellular matrix protein localization, and gene expression of human mesenchymal stromal cells (hMSCs) differentiated on the fibrous scaffolds PLLA/Col/HA, PLLA/Col, and PLLA/HA were also analyzed. The electrospun scaffolds with a diameter of 200-950 nm demonstrated well-formed interconnected fibrous network structure, which supported the growth of hMSCs. When compared with PLLA/H%A and PLLA/Col scaffolds, PLLA/Col/HA scaffolds presented a higher density of viable cells and significant upregulation of genes associated with osteogenic lineage, which were achieved without the use of specific medium or growth factors. These results were supported by the elevated levels of calcium, osteocalcin, and mineralization (P<0.05) observed at different time points (0, 7, 14, and 21 days). Furthermore, electron microscopic observations and fibronectin localization revealed that PLLA/Col/HA scaffolds exhibited superior osteoinductivity, when compared with PLLA/Col or PLLA/HA scaffolds. These findings indicated that the fibrous structure and synergistic action of Col and nano-HA with high-molecular-weight PLLA played a vital role in inducing osteogenic differentiation of hMSCs. The data obtained in this study demonstrated that the developed fibrous PLLA/Col/HA biocomposite scaffold may be supportive for stem cell based therapies for bone repair, when compared with the other two scaffolds.

Matched MeSH terms: Collagen
A fibril-based structural constitutive theory reveals the dominant role of network characteristics on the mechanical behavior of fibroblast-compacted collagen gels

Feng Z, Ishiguro Y, Fujita K, Kosawada T, Nakamura T, Sato D, et al.

Biomaterials, 2015 Oct;67:365-81.
PMID: 26247391 DOI: 10.1016/j.biomaterials.2015.07.038

In this paper, we present a general, fibril-based structural constitutive theory which accounts for three material aspects of crosslinked filamentous materials: the single fibrillar force response, the fibrillar network model, and the effects of alterations to the fibrillar network. In the case of the single fibrillar response, we develop a formula that covers the entropic and enthalpic deformation regions, and introduce the relaxation phase to explain the observed force decay after crosslink breakage. For the filamentous network model, we characterize the constituent element of the fibrillar network in terms its end-to-end distance vector and its contour length, then decompose the vector orientation into an isotropic random term and a specific alignment, paving the way for an expanded formalism from principal deformation to general 3D deformation; and, more important, we define a critical core quantity over which macroscale mechanical characteristics can be integrated: the ratio of the initial end-to-end distance to the contour length (and its probability function). For network alterations, we quantitatively treat changes in constituent elements and relate these changes to the alteration of network characteristics. Singular in its physical rigor and clarity, this constitutive theory can reproduce and predict a wide range of nonlinear mechanical behavior in materials composed of a crosslinked filamentous network, including: stress relaxation (with dual relaxation coefficients as typically observed in soft tissues); hysteresis with decreasing maximum stress under serial cyclic loading; strain-stiffening under uniaxial tension; the rupture point of the structure as a whole; various effects of biaxial tensile loading; strain-stiffening under simple shearing; the so-called "negative normal stress" phenomenon; and enthalpic elastic behaviors of the constituent element. Applied to compacted collagen gels, the theory demonstrates that collagen fibrils behave as enthalpic elasticas with linear elasticity within the gels, and that the macroscale nonlinearity of the gels originates from the curved fibrillar network. Meanwhile, the underlying factors that determine the mechanical properties of the gels are clarified. Finally, the implications of this study on the enhancement of the mechanical properties of compacted collagen gels and on the cellular mechanics with this model tissue are discussed.

Matched MeSH terms: Collagen/pharmacology*
A hyperelastic fibre-reinforced continuum model of healing tendons with distributed collagen fibre orientations

Bajuri MN, Isaksson H, Eliasson P, Thompson MS

Biomech Model Mechanobiol, 2016 12;15(6):1457-1466.
PMID: 26951049

The healing process of ruptured tendons is problematic due to scar tissue formation and deteriorated material properties, and in some cases, it may take nearly a year to complete. Mechanical loading has been shown to positively influence tendon healing; however, the mechanisms remain unclear. Computational mechanobiology methods employed extensively to model bone healing have achieved high fidelity. This study aimed to investigate whether an established hyperelastic fibre-reinforced continuum model introduced by Gasser, Ogden and Holzapfel (GOH) can be used to capture the mechanical behaviour of the Achilles tendon under loading during discrete timepoints of the healing process and to assess the model's sensitivity to its microstructural parameters. Curve fitting of the GOH model against experimental tensile testing data of rat Achilles tendons at four timepoints during the tendon repair was used and achieved excellent fits ([Formula: see text]). A parametric sensitivity study using a three-level central composite design, which is a fractional factorial design method, showed that the collagen-fibre-related parameters in the GOH model-[Formula: see text] and [Formula: see text]-had almost equal influence on the fitting. This study demonstrates that the GOH hyperelastic fibre-reinforced model is capable of describing the mechanical behaviour of healing tendons and that further experiments should focus on establishing the structural and material parameters of collagen fibres in the healing tissue.

Matched MeSH terms: Collagen/chemistry*
A new histological score grade for deep partial-thickness burn wound healing process

Guo HF, Mohd Ali R, Abd Hamid R, Chang SK, Zainal Z, Khaza'ai H

Int J Burns Trauma, 2020;10(5):218-224.
PMID: 33224609

Burns are injuries on the skin or other tissues. Burns are divided into superficial, partial, and full-thickness, characterized by the depth of the affected tissues. Histological analysis is critical to assess the burn wound healing process. Thus, a systematic evaluation system is imperative for burn research. In the present study, a total of thirty Sprague-Dawley rats were randomly divided into five groups. Deep partial-thickness burn wound was induced on the dorsal part of the rats. Six animals from each group were sacrificed on the 3rd, 7th, 11th, 14th and 21st day post-burn, respectively. Half of the wound tissue was immediately fixed in buffered neutral formalin for hematoxylin & eosin staining. The healing of the epidermis was evaluated with scores ranging from 0 to 7 based on the state of crust on wound surface, the degree of epithelialization as well as the formation of rete ridges. Meanwhile, healing of the dermis was also evaluated with scores ranging from 0 to 7 according to the proportion of adipose cells, inflammatory cells and fibroblasts, the state of collagen deposition as well as the formation of hair follicles. Furthermore, temporal changes of histological score of epidermis and dermis in the skin tissue with deep partial-thickness burn was evaluated. In conclusion, a new comprehensive system for assessing microscopic changes in the healing process of deep partial-thickness burn wound in hematoxylin & eosin staining slides was established, which simplified the scoring process and helped to obtain reproducible and accurate results in the burn study.

Matched MeSH terms: Collagen
A note concerning the possibility that the lesions in scurvy are due to a failure to produce 'compact' collagen fibres

Candlish J

Med J Malaya, 1966 Dec;21(2):161-3.
PMID: 4227387
Matched MeSH terms: Collagen/biosynthesis*
Fulltext A novel de novo mutation in COL2A1 gene associated with fetal skeletal dysplasia

Chu FC, Hii LY, Hung TH, Lo LM, Hsieh TT, Shaw SW

Taiwan J Obstet Gynecol, 2021 Mar;60(2):359-362.
PMID: 33678343 DOI: 10.1016/j.tjog.2021.01.017

OBJECTIVE: Skeletal dysplasias, caused by genetic mutations, are a heterogenous group of heritable disorders affecting bone development during fetal life. Stickler syndrome, one of the skeletal dysplasias, is an autosomal dominant connective tissue disorder caused by abnormal collagen synthesis owing to a genetic mutation in COL2A1.
CASE REPORT: We present the case of a 38-year-old multipara woman whose first trimester screening showed a normal karyotype. However, the bilateral femur and humerus length symmetrically shortened after 20 weeks. Next-generation sequencing for mutations in potential genes leading to skeletal dysplasia detected a novel de novo mutation (c.1438G > A, p.Gly480Arg) in COL2A1, causing Stickler syndrome type 1. This pathogenic mutation might impair or destabilize the collagen structure, leading to collagen type II, IX, and XI dysfunction.
CONCLUSION: We identified a novel de novo mutation in COL2A1 related to the STL1 syndrome and delineated the extent of the skeletal dysplasia disease spectrum.

Matched MeSH terms: Collagen Type II/genetics*
A novel wound healing accelerator: Effect of vitreous gel of cow eyeball on a chronic wound model

Makhmudi A, Wirohadidjojo YW, Gahara E, Noor HZ, Sunardi M, Mahmudah NA, et al.

Med J Malaysia, 2020 11;75(6):698-704.
PMID: 33219180

INTRODUCTION: Several studies have reported the disturbance in the process of wound healing after administration of mitomycin-C, which inhibits granulation tissue formation and collagen synthesis, resulting in chronic wounds. The vitreous gel of cow eyeballs contains a high level of hyaluronic acid, which has a role in inflammation, granulation, re-epithelialization, and remodelling. This study aims to understand the effect of 1% povidone iodine and vitreous gel of cow eyeballs on wound healing after administration of mitomycin-C.
METHODS: This was an in vivo study with quasi-experimental methods on 32 Wistar mice. Full-thickness wounds were made and then treated with mitomicyn-C. The mice were divided into 4 groups: a control group with NaCl 0.9% vitreous gel of cow eyeball (VGCE), 1% povidone-iodine, and a combination of VGCE and 1% povidone-iodine groups. Macroscopic and microscopic observations of the process of wound healing were performed on days 3, 7, and 14.
RESULTS: Vitreous gel administration produced significant wound healing rates within the first three days, and histological analysis revealed an increased number of fibroblasts and polymorphonuclear cells. However, the povidone iodine group and the combination group with vitreous gel did not produce significant results.
CONCLUSION: The single administration of VGCE can accelerate the wound healing process, increase the number of fibroblasts, and reduce inflammation in a chronic wound model.

Matched MeSH terms: Collagen
A preliminary study of the effects of glucosamine sulphate and chondroitin sulphate on surgically treated and untreated focal cartilage damage

Kamarul T, Ab-Rahim S, Tumin M, Selvaratnam L, Ahmad TS

Eur Cell Mater, 2011 Mar 15;21:259-71; discussion 270-1.
PMID: 21409755

The effects of Glucosamine Sulphate (GS) and Chondroitin Sulphate (CS) on the healing of damaged and repaired articular cartilage were investigated. This study was conducted using 18 New Zealand white rabbits as experimental models. Focal cartilage defects, surgically created in the medial femoral condyle, were either treated by means of autologous chondrocyte implantation (ACI) or left untreated as controls. Rabbits were then divided into groups which received either GS+/-CS or no pharmacotherapy. Three rabbits from each group were sacrificed at 12 and 24 weeks post-surgery. Knees dissected from rabbits were then evaluated using gross quantification of repair tissue, glycosaminoglycan (GAG) assays, immunoassays and histological assessments. It was observed that, in contrast to untreated sites, surfaces of the ACI-repaired sites appeared smooth and continuous with the surrounding native cartilage. Histological examination demonstrated a typical hyaline cartilage structure; with proteoglycans, type II collagen and GAGs being highly expressed in repair areas. The improved regeneration of these repair sites was also noted to be significant over time (6 months vs. 3 months) and in GS and GS+CS groups compared to the untreated (without pharmacotherapy) group. Combination of ACI and pharmacotherapy (with glucosamine sulphate alone/ or with chondroitin sulphate) may prove beneficial for healing of damaged cartilage, particularly in relation to focal cartilage defects.

Matched MeSH terms: Collagen Type II/metabolism
Fulltext A study protocol: spinal morphology, physical performance, quality of life and biochemical markers in adults at risk of osteoporotic fractures

Chua, S.K., Singh, Devinder K.A., Rajaratnam, B.S., Mokhtar, Sabarul A., Sridharan, R., Gan, K.B., et al.

Pertanika Journal of Science & Technology, 2017;25(4):1123-1134.
MyJurnal

Older adults are at risk of osteoporotic fractures. Osteoporotic vertebral fractures are associated with a reduced cross-sectional area and muscle strength of the back extensor muscles, increased intramuscular fat infiltration and thoracic and lumbar curvature alterations. This study proposed a protocol to examine in more detail the contributions of altered spinal morphological, physical performance and biochemical markers to the risk of developing osteoporotic vertebral fractures. In this cross-sectional study, we plan to recruit 100 adults aged 50 years and above from an orthopaedic clinic, Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan Malaysia. The fracture prediction tool (FRAX) will be used to categorise high and low risk groups. Back muscle strength will be quantified using a load cell system. Thoracolumbar curvatures will be examined using an electromagnetic tracking system and intramuscular fat infiltration in the lumbar muscles will be measured using Magnetic Resonance Imaging. The Short Physical Performance Battery and JAMA dynamometer will quantify physical performance and the European Quality of Life Questionnaire will be used to assess self-perceived quality of life. Biochemical markers of serum C terminal telopeptide and N terminal propeptide of type I procollagen will be assessed using an enzyme-linked immunosorbent assays kit. A spine-specific model using regression analysis will be developed to predict osteoporotic vertebral fractures using the measured parameters in the present study.

Matched MeSH terms: Collagen Type I
Fulltext A three-dimensional collagen construct to model lipopolysaccharide-induced activation of BV2 microglia

Haw RT, Tong CK, Yew A, Lee HC, Phillips JB, Vidyadaran S

J Neuroinflammation, 2014 Jul 30;11:134.
PMID: 25074682 DOI: 10.1186/1742-2094-11-134

BACKGROUND: We report a novel method of culturing microglia in three dimension (3D) using collagen as a substrate. By culturing microglia within a matrix, we aim to emulate the physical state of microglia embedded within parenchyma.
METHODS: BV2 microglia cell suspensions were prepared with type I collagen and cast into culture plates. To characterise the BV2 microglia cultured in 3D, the cultures were evaluated for their viability, cell morphology and response to lipopolysaccharide (LPS) activation. Conventional monolayer cultures (grown on uncoated and collagen-coated polystyrene) were set up concurrently for comparison.
RESULTS: BV2 microglia in 3D collagen matrices were viable at 48 hrs of culture and exhibit a ramified morphology with multiplanar cytoplasmic projections. Following stimulation with 1 μg/ml LPS, microglia cultured in 3D collagen gels increase their expression of nitric oxide (NO) and CD40, indicating their capacity to become activated within the matrix. Up to 97.8% of BV2 microglia grown in 3D cultures gained CD40 positivity in response to LPS, compared to approximately 60% of cells grown in a monolayer (Pcollagen gels also showed increased mRNA and protein expression of inflammatory cytokines IL-6, TNF-α and the chemoattractant MCP-1 following LPS stimulation.
CONCLUSIONS: In summary, BV2 microglia cultured in 3D collagen hydrogels exhibit multiplanar cytoplasmic projections and undergo a characteristic and robust activation response to LPS. This culture system is accessible to a wide range of analyses and provides a useful new in vitro tool for research into microglial activation.

Matched MeSH terms: Collagen/metabolism*; Collagen/ultrastructure
AFM analysis of collagen fibrils in expanded scalp tissue after anisotropic tissue expansion

Aziz J, Ahmad MF, Rahman MT, Yahya NA, Czernuszka J, Radzi Z

Int J Biol Macromol, 2018 Feb;107(Pt A):1030-1038.
PMID: 28939521 DOI: 10.1016/j.ijbiomac.2017.09.066

Successful use of tissue expanders depends on the quality of expanded tissue. This study evaluates the impact of anisotropic self-inflating tissue expander (SITE) on the biomechanics of skin. Two different SITE were implanted subcutaneously on sheep scalps; SITE that requires 30days for maximum expansion (Group A; n=5), and SITE that requires 21days for maximum expansion (Group B; n=5). Control animals (n=5) were maintained without SITE implantation. Young's Modulus, D-periodicity, overlap and gap region length, diameter, and height difference between overlap and gap regions on collagen fibrils were analyzed using atomic force microscopy. Histology showed no significant differences in dermal thickness between control and expanded skin of groups A and B. Furthermore, most parameters of expanded skin were similar to controls (p>0.05). However, the height difference between overlap and gap regions was significantly smaller in group B compared to both control and group A (p<0.01). Strong correlation was observed between Young's Modulus of overlap and gap regions of the control and group A, but not group B. Results suggest that a relatively slower SITE can be useful in reconstructive surgery to maintain the biomechanical properties of expanded skin.

Matched MeSH terms: Collagen/ultrastructure; Collagen/chemistry*
Fulltext Acceleration of wound healing by orthosiphon stamineus leaf extract in rats

Mahmood, A.A., Hapipah, M.A., Noor, S.M., Kuppusamy, U.R., Salmah, I., Salmah, I., et al.

ASM Science Journal, 2009;3(1):51-57.
MyJurnal

The effects of topical application of Orthosiphon stamineus leaf extract on the rate of wound healing and histology of the healed wound were assessed. Four groups of adult male Sprague Dawley rats were experimentally wounded in the posterior neck area. A thin layer of blank placebo was applied topically to wounds of Group 1 rats. Wounds of experimental animals (Group 2 and 3) were dressed with placebo containing 5% and 10% O. stamineus extract, respectively. A thin layer of Intrasite gel® was applied topically to wounds of Group 4 animals as reference. Macroscopically, wounds dressed with placebo containing 5% (healed on day 14.50 ± 0.43) and 10% (healed on day 13.83 ± 0.21) O. stamineus extract each or Intrasite gel® (healed on day 13.13 ± 0.42) significantly accelerated the rate of wound healing compared to wounds dressed with blank placebo. Histological analysis of healed wounds confirmed the results. Wounds dressed with placebo containing 5%, 10% O.stamineus or Intrasite gel® showed markedly less scar width at wound enclosure and granulating tissue contained markedly more collagen, proliferating fibroblast with angiogenesis, and no inflammatory cells compared to wounds dressed with blank placebo. In conclusion, placebo containing 5% or 10% O. stamineus on extract-dressed wounds significantly accelerated the rate of wound healing in rats.

Matched MeSH terms: Collagen
Fulltext Acute Wound Healing Potential of Marine Worm, Diopatra claparedii Grube, 1878 Aqueous Extract on Sprague Dawley Rats

Che Soh N', Rapi HS, Mohd Azam NS, Santhanam RK, Assaw S, Haron MN, et al.

Evid Based Complement Alternat Med, 2020;2020:6688084.
PMID: 33488747 DOI: 10.1155/2020/6688084

Diopatra claparedii which is colloquially known as Ruat Sarung can be found along the west coast of Peninsular Malaysia. The species has a unique ability to regenerate anterior and posterior segments upon self-amputation or injury, thus having potential as a wound healing promoter. In this study, the wound healing potential of D. claparedii aqueous extract on acute wound model in rats was revealed for the first time. Various concentrations (0.1%, 0.5%, and 1.0% w/w) of D. claparedii ointment were formulated and tested on Sprague Dawley rats through topical application on full-thickness skin wounds for 14 days. The wound healing effects were investigated via behaviour observation, wound contraction, and histopathological analysis. Quality assessment was performed via skin irritation test, microbial contamination test (MCT), and heavy metal detection. The study also included test for antibacterial activities and detection of bioactive compounds in D. claparedii. One percent of D. claparedii ointment showed rapid wound healing potential with good soothing effects and more collagen deposition in comparison to the commercial wound healing ointments such as acriflavine (0.1% w/v) and traditional ointment gamat (sea cucumber extract) (15.0% w/v). No local skin irritation, microbial contamination, and insignificant concentration of heavy metals were observed, which indicate its safe application. Moreover, the aqueous extract of D. claparedii exhibited antibacterial activities against Escherichia coli and Pseudomonas aeruginosa with minimum inhibitory concentration (MIC) value at 0.4 g/ml. 1H NMR analysis of the aqueous extract of D. claparedii revealed some metabolites that might be responsible for its wound healing properties such as amino acids, halogenated aromatics, organic acids, vitamins, and others. Altogether, these results suggested that the aqueous extract of D. claparedii could be utilised as an alternative natural wound healing promoter.

Matched MeSH terms: Collagen
Alteration of the bone tissue material properties in type 1 diabetes mellitus: A Fourier transform infrared microspectroscopy study

Mieczkowska A, Mansur SA, Irwin N, Flatt PR, Chappard D, Mabilleau G

Bone, 2015 Jul;76:31-9.
PMID: 25813583 DOI: 10.1016/j.bone.2015.03.010

Type 1 diabetes mellitus (T1DM) is a severe disorder characterized by hyperglycemia and hypoinsulinemia. A higher occurrence of bone fractures has been reported in T1DM, and although bone mineral density is reduced in this disorder, it is also thought that bone quality may be altered in this chronic pathology. Vibrational microscopies such as Fourier transform infrared microspectroscopy (FTIRM) represent an interesting approach to study bone quality as they allow investigation of the collagen and mineral compartment of the extracellular matrix in a specific bone location. However, as spectral feature arising from the mineral may overlap with those of the organic component, the demineralization of bone sections should be performed for a full investigation of the organic matrix. The aims of the present study were to (i) develop a new approach, based on the demineralization of thin bone tissue section to allow a better characterization of the bone organic component by FTIRM, (ii) to validate collagen glycation and collagen integrity in bone tissue and (iii) to better understand what alterations of tissue material properties in newly forming bone occur in T1DM. The streptozotocin-injected mouse (150 mg/kg body weight, injected at 8 weeks old) was used as T1DM model. Animals were randomly allocated to control (n = 8) or diabetic (n = 10) groups and were sacrificed 4 weeks post-STZ injection. Bones were collected at necropsy, embedded in polymethylmethacrylate and sectioned prior to examination by FTIRM. FTIRM collagen parameters were collagen maturity (area ratio between 1660 and 1690 cm(-1) subbands), collagen glycation (area ratio between the 1032 cm(-1) subband and amide I) and collagen integrity (area ratio between the 1338 cm(-1) subband and amide II). No significant differences in the mineral compartment of the bone matrix could be observed between controls and STZ-injected animals. On the other hand, as compared with controls, STZ-injected animals presented with significant higher value for collagen maturity (17%, p = 0.0048) and collagen glycation (99%, p = 0.0121), while collagen integrity was significantly lower by 170% (p = 0.0121). This study demonstrated the profound effect of early T1DM on the organic compartment of the bone matrix in newly forming bone. Further studies in humans are required to ascertain whether T1DM also lead to similar effect on the quality of the bone matrix.

Matched MeSH terms: Collagen/metabolism
Fulltext An Overview of In Vitro, In Vivo, and Computational Techniques for Cancer-Associated Angiogenesis Studies

Rahman HS, Tan BL, Othman HH, Chartrand MS, Pathak Y, Mohan S, et al.

Biomed Res Int, 2020;2020:8857428.
PMID: 33381591 DOI: 10.1155/2020/8857428

Angiogenesis is a crucial area in scientific research because it involves many important physiological and pathological processes. Indeed, angiogenesis is critical for normal physiological processes, including wound healing and embryonic development, as well as being a component of many disorders, such as rheumatoid arthritis, obesity, and diabetic retinopathies. Investigations of angiogenic mechanisms require assays that can activate the critical steps of angiogenesis as well as provide a tool for assessing the efficacy of therapeutic agents. Thus, angiogenesis assays are key tools for studying the mechanisms of angiogenesis and identifying the potential therapeutic strategies to modulate neovascularization. However, the regulation of angiogenesis is highly complex and not fully understood. Difficulties in assessing the regulators of angiogenic response have necessitated the development of an alternative approach. In this paper, we review the standard models for the study of tumor angiogenesis on the macroscopic scale that include in vitro, in vivo, and computational models. We also highlight the differences in several modeling approaches and describe key advances in understanding the computational models that contributed to the knowledge base of the field.

Matched MeSH terms: Collagen
An investigation of the antiplatelet effects of succinobucol (AGI-1067)

Houston SA, Ugusman A, Gnanadesikan S, Kennedy S

Platelets, 2017 May;28(3):295-300.
PMID: 27681689 DOI: 10.1080/09537104.2016.1218456

Succinobucol is a phenolic antioxidant with anti-inflammatory and antiplatelet effects. Given the importance of oxidant stress in modulating platelet-platelet and platelet-vessel wall interactions, the aim of this study was to establish if antioxidant activity was responsible for the antiplatelet activity of succinobucol. Platelet aggregation in response to collagen and adenosine diphosphate (ADP) was studied in rabbit whole blood and platelet-rich plasma using impedance aggregometry. The effect of oxidant stress on aggregation, platelet lipid peroxides, and vascular tone was studied by incubating platelets, washed platelets or preconstricted rabbit iliac artery rings respectively with a combination of xanthine and xanthine oxidase (X/XO). To study the effect of succinobucol in vivo, anaesthetized rats were injected with up to 150 mg/kg succinobucol and aggregation measured in blood removed 15 mins later. Succinobucol (10-5-10-4M) significantly attenuated platelet aggregation to collagen and ADP in whole blood and platelet-rich plasma. X/XO significantly increased aggregation to collagen and platelet lipid peroxides and this was reversed by succinobucol. Addition of X/XO to denuded rabbit iliac arteries caused a dose-dependent relaxation which was significantly inhibited by succinobucol. In vivo administration up to 150 mg/kg had no effect on heart rate or mean arterial blood pressure but significantly inhibited platelet aggregation to collagen ex vivo. In conclusion, succinobucol displays anti-platelet activity in rabbit and rat blood and reverses the increase in platelet aggregation in response to oxidant stress.

Matched MeSH terms: Collagen/antagonists & inhibitors; Collagen/pharmacology

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