Study on the microstructure of African wild silk cocoon shells and fibers

Teshome, Addis; Vollrath, Fritz; Raina, Satish; Kabaru, J. M.; Onyari, John Mmari

doi:10.1016/j.ijbiomac.2011.09.025

Cited by 15 publications

(11 citation statements)

References 17 publications

(16 reference statements)

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“…One of the earlier report, indicated the presence of crystals on the surface of the cocoon [24]. Thereafter those crystals are identified as calcium oxalate monohydrate by X-ray diffraction (XRD) studies [15,25]. Another study further demonstrated that these crystals are formed in the larval gut [26].…”

Section: Edax Analysismentioning

confidence: 99%

“…Our results show that without the presence of calcium oxalate monohydrate, a delay of CO 2 passage from outside to inside could be directly related to the weaving of silk thread. This is important in the sense that there are different version of cocoons where the deposition of calcium oxalate hydrate type of crystals on the outer surface varies [15,18]. Therefore it is the calcium oxalate crystals which predominantly prevents the passage of CO 2 from outside to inside.…”

Section: O 2 Flow Across the Cocoon Membranementioning

confidence: 99%

“…It is of interest to understand how silk cocoon membrane performs such activity based on their porous structure, mechanical strength, and its potential for control of the gaseous environment and temperature inside. One should try to understand, how life inside a narrow confinement of cocoon breath for so many days and the most important aspect here is to address the structure of cocoons which is optimized to function in such a manner [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Carbondioxide Gating in Silk Cocoon

Roy¹,

Meena²,

Kusurkar³

et al. 2012

Biointerphases

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Silk is the generic name given to the fibrous proteins spun by a number of arthropods. During metamorphosis, the larva of the silk producing arthropods excrete silk-fiber from its mouth and spun it around the body to form a protective structure called cocoon. An adult moth emerges out from the cocoon after the dormant phase (pupal phase) varying from 2 weeks to 9 months. It is intriguing how CO 2 /O 2 and ambient temperature are regulated inside the cocoon during the development of the pupa. Here we show that the cocoon membrane is asymmetric, it allows preferential gating of CO 2 from inside to outside and it regulates a physiological temperature inside the cocoon irrespective of the surrounding environment temperature. We demonstrate that under simulating CO 2 rich external environment, the CO 2 does not diffuse inside the cocoon. Whereas, when CO 2 was injected inside the cocoon, it diffuses out in 20 s, indicating gating of CO 2 from inside to outside the membrane. Removal of the calcium oxalate hydrate crystals which are naturally present on the outer surface of the cocoon affected the complete blockade of CO 2 flow from outside to inside suggesting its role to trap most of the CO 2 as hydrogen bonded bicarbonate on the surface. The weaved silk of the cocoon worked as the second barrier to prevent residual CO 2 passage. Furthermore, we show that under two extreme natural temperature regime of 5 and 50°C, a temperature of 25 and 34°C respectively were maintained inside the cocoons. Our results demonstrate, how CO 2 gating and thermoregulation helps in maintaining an ambient atmosphere inside the cocoon for the growth of pupa. Such natural architectural control of gas and temperature regulation could be helpful in developing energy saving structures and gas filters.

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Section: Edax Analysismentioning

confidence: 99%

Section: O 2 Flow Across the Cocoon Membranementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Carbondioxide Gating in Silk Cocoon

Roy¹,

Meena²,

Kusurkar³

et al. 2012

Biointerphases

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show abstract

“…Some silks already explored for biomaterial such as Bombyxmorifrom domesticated mulberry silkworm or from non-mulberry silk such as Antheraeamylitta, Antheraeaassamenis, Antheraeapernyi, Philosamiaricini, Samiacyn-thiaricini [1]. Other African source of non-mulberry wild silkworm cocoon also come in to attention like Gonometapostica, Epiphorabauhiniae, Anaphe panda, and Argemamimosae [3]. In Japan, The wild silk from species Samiacyn-thiaricini was well studied to obtain the fibroin from its cocoo [4].…”

Section: Introductionmentioning

confidence: 99%

Indigenous Indonesian Wild Silkworm Cocoon of Attacus atlas as Biocompatible Film Biomaterial

Nindhia¹,

Knejzlı́k²,

Ruml³

et al. 2017

IOP Conf. Ser.: Mater. Sci. Eng.

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Abstract. The biocompatible film made from wild silkworm cocoon of Attacus atlas is intorduced in this research for anticipation of demand on biocompatible film for regenerative medicine. The wild silkworm cocoon was indigenous Indonesia and was taken from it original location in Indonesia. Protocol for degumming method was obtained in this research by using treatment with NaOH solution at 0.1 M for 1 hour. The film was prepared by grinding the wet degummed fiber until pulp like state was obtained. The mixture was dropped in sequence on the hot ceramic plate with temperature around 60 o C. The film thickness can be controlled precisely by using this technique. The film is soaked in alcohor for 1 day for stability testing and the result is found stable. The film is introduced in to COS-1 Cell suspension with previously washed in PBS solution and put in a chamber for biocompatibility testing. The cell are found able to grow and attach in first day observation and dramatically increase after 3 days observation. This is an indicate that the film that is produced from wild silkworm cocon of Attacus atlas has excellent biocompatibility.

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“…β-sheet crystal is determined the stiffness, strength, and optical properties of silk, which structural changes is occurred in the stretching of silk fibers [5]. Moreover, other types of cocoon silk (African wild cocoon silk) are also studied and revealed that cocoon shells are multilayered and porous structures constructed from highly cross-linked fibers [6]. However, as biomedical materials, cocoon silk is dissolved in different solution systems (i.e.…”

Section: Introductionmentioning

confidence: 99%

Multifunctional Cocoon Silk Prepared by Plasma Treatment

Li¹,

Ming²,

Yang³

et al. 2017

JTEFT

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Multifunctionality has become the key metrics for cocoon silk applications as textile materials. In this study, plasma treatment, a simple and effective method, is used to prepare multifunctional cocoon silks with electrical conductivity and water repellency. The results show Cu/CuO particles are covered on the surface of cocoon silks, which ion's attachment amounts are not affected by different varieties of cocoon silks. Comparing with resistance values, the conductivity of Cu-sputtered FS was σ = 1×10 -6 S cm -1, however, the conductivity of Cu-sputtered DS was σ = 5 × 10 -10 S cm -1 . The capillary height of pure DS cocoon silk is 2.5mm within 9h, obviously higher than water-repellent treatment samples. Nevertheless, the strain of ion-sputtered cocoon silk is slightly decreasing. This multifunctionalzed cocoon silk satisfies the market demand for natural "smart" products, and is a promising practical material for use in the textile industry.

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Study on the microstructure of African wild silk cocoon shells and fibers

Cited by 15 publications

References 17 publications

Carbondioxide Gating in Silk Cocoon

Carbondioxide Gating in Silk Cocoon

Indigenous Indonesian Wild Silkworm Cocoon of Attacus atlas as Biocompatible Film Biomaterial

Multifunctional Cocoon Silk Prepared by Plasma Treatment

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