Bioinspired materials: from low to high dimensional structure

The surprising properties of biomaterials are the results of billions of years of evolution. Generally, biomaterials are assembled under mild conditions with very limited supply of constituents available for living organism, and their amazing properties largely result from the sophisticated hierarchical structures. Following the biomimetic principles to prepare manmade materials has drawn great research interests in materials science and engineering. In this review, we summarize the recent progress in fabricating bioinspired materials with the emphasis on mimicking the structure from one to three dimensions. Selected examples are described with a focus on the relationship between the structural characters and the corresponding functions. For one-dimensional materials, spider fibers, polar bear hair, multichannel plant roots and so on have been involved. Natural structure color and color shifting surfaces, and the antifouling, antireflective coatings of biomaterials are chosen as the typical examples of the two-dimensional biomimicking. The outstanding protection performance, and the stimuli responsive and self-healing functions of biomaterials based on the sophisticated hierarchical bulk structures are the emphases of the three-dimensional mimicking. Finally, a summary and outlook are given.

Mimicking π Backdonation in Ce-MOFs for Solar-Driven Ammonia Synthesis

π Backdonation is the core process to break through the kinetically complex and energetic hurdle for catalyzing effectively the NH₃ synthesis but only occurs on certain transition metals with empty and filled d orbitals. Herein, mimicking π backdonation enables MOF-76(Ce) materials to convert N₂/NH₃ effectively. Note that, by virtue of the intrinsic mechanism of ligand-to-metal charge transfer, metal cerium species in MOF-76(Ce) serve as an electron sink for accumulating the photogenerated electrons. Taken together, experimental and theoretical analyses reveal that such metal cerium species with coordination unsaturated state (Ce-CUS) on a MOF-76(Ce) nanorod surface can also provide unoccupied and occupied 4f orbitals to accept from and then donate electrons back to nitrogen molecules. Remarkably, it shows outstanding photocatalytic nitrogen reduction performance with high average NH₃ yield (34 μmol g^-1 h^-1) under ambient conditions. This work provides fresh insights into rational designing and engineering highly active catalysts with rare earth elements.

A giant solid cavernous hemangioma mimicking sphenoid wing meningioma in an adolescent: A case report

RATIONALE

Central nervous system (CNS) solid cavernous hemangiomas are rare extra-axial anomalies that may sometimes resemble meningiomas. Due to their complex vascular nature, accurate preoperative diagnosis is important to avoid disastrous hemorrhage during operation. To the best of our knowledge this is the first case in an adolescent since all middle cranial fossa hemangioma cases reported in literature are adults in their 40s or 50s and all the pediatric cases are cystic.

PATIENT CONCERNS

We present a case of a 14-year-old girl with headache and dizziness for 3 months. She occasionally experienced nausea and vomiting but denied visual disturbances and loss of smell.

DIAGNOSES

MRI revealed a lesion that extends to the greater wing of the sphenoid bone as well as the pituitary fossa. Our initial diagnosis was a sphenoid wing meningioma but interestingly, histopathology revealed solid cavernous hemangioma.

INTERVENTIONS

The residual tumor was completely removed with 2 sessions of Gamma Knife radiotherapy after surgery.

OUTCOMES

We were confronted with excessive bleeding during surgery so we attained subtotal resection. However, the patient recovered well with no recurrence of the tumor.

LESSONS

Our case shows that space occupying lesions involving the cavernous sinus and sphenoid ridged could be easily misdiagnosed as sphenoid wing meningiomas in children and adolescents and even adults therefore great care must be exercised when confronted with this kind of presentation.

Modified porous scaffolds of silk fibroin with mimicked microenvironment based on decellularized pulp/fibronectin for designed performance biomaterials in maxillofacial bone defect

Maxillofacial bone defect is a critical problem for many patients. In severe cases, the patients need an operation using a biomaterial replacement. Therefore, to design performance biomaterials is a challenge for materials scientists and maxillofacial surgeons. In this research, porous silk fibroin scaffolds with mimicked microenvironment based on decellularized pulp and fibronectin were created as for bone regeneration. Silk fibroin scaffolds were fabricated by freeze-drying before modification with three different components: decellularized pulp, fibronectin, and decellularized pulp/fibronectin. The morphologies of the modified scaffolds were observed by scanning electron microscopy. Existence of the modifying components in the scaffolds was proved by the increase in weights and from the pore size measurements of the scaffolds. The modified scaffolds were seeded with MG-63 osteoblasts and cultured. Testing of the biofunctionalities included cell viability, cell proliferation, calcium content, alkaline phosphatase activity (ALP), mineralization and histological analysis. The results demonstrated that the modifying components organized themselves into aggregations of a globular structure. They were arranged themselves into clusters of aggregations with a fibril structure in the porous walls of the scaffolds. The results showed that modified scaffolds with a mimicked microenvironment of decellularized pulp/fibronectin were suitable for cell viability since the cells could attach and spread into most of the pores of the scaffold. Furthermore, the scaffolds could induce calcium synthesis, mineralization, and ALP activity. The results indicated that modified silk fibroin scaffolds with a mimicked microenvironment of decellularized pulp/fibronectin hold promise for use in tissue engineering in maxillofacial bone defects. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1624-1636, 2017.

Castleman disease in the parapharyngeal space: a case report and review of the literature

Castleman disease is most commonly found in the mediastinum, while the head and neck is the second most common location. The disease exists in a unicentric and multicentric variety and is usually successfully treated with surgical resection alone. Early identification is important for treatment planning. Castleman disease has been reported to mimic other disease processes, however there has been only one report of the disease mimicking a nerve sheath tumor in the parapharyngeal space. Here we report the second case of Castleman disease mimicking a schwannoma in the parapharyngeal space.

White Epidermoid of the Sylvian Fissure Masquerading as a Dermoid Cyst: An Extremely Rare Occurrence

We report the case of a 30-year-old female with a Sylvian fissure, white epidermoid which was radiologically looking like a dermoid cyst. The female presented with a headache with no neurological deficits. On radiology, the lesion was in Sylvian fissure, T1 hyperintense, T2 hypointense, and with minimal diffusion restriction medially. Hence a preoperative impression of dermoid cyst was made, a quite uncommon location. Intraoperatively, the classical pearly-white flaky appearance of epidermoid was seen which was confirmed histopathologically. White epidermoids appearing so because of high protein content are a rarity and are more likely to cause aseptic meningitis in the event of intraoperative spillage. Differentiating between a dermoid cyst and white epidermoid preoperatively and radiologically is difficult. Dermoids show diffusion restriction and are usually midline, whereas white epidermoids do not show diffusion restriction and are usually lateral. This is the first report of a white epidermoid in Sylvian fissure to the best of our knowledge.

Local ALK-Positive Histiocytosis With Unusual Morphology and Novel TRIM33-ALK Gene Fusion

ALK-positive histiocytosis was first described in 2008 as a systemic histiocytic disorder involving young infants and neonates. Subsequently, cases of local ALK-positive histiocytosis as well as clinical presentation in adult patients have been increasingly reported in the literature. The current case documented the hitherto largest local ALK-positive histiocytosis lesion involving the mesentery of a 20-year-old female patient, a clinical presentation that has not been previously reported in the medical literature. Of note was the presence of numerous lymphocytes, plasma cells, and eosinophils as well as the formation of lymphoid follicles in the lesion, mimicking an inflammatory myofibroblastic tumor. Other unique histologic aspects of the current case included the nested arrangement of the histiocytes, intravascular extension of the histiocytic proliferation into a large vein, and tumor necrosis. Notably, molecular studies revealed a novel TRIM33 (exon 12)-ALK (exon 20) gene fusion. Therefore, ALK-positive histiocytosis with TRIM33-ALK gene fusion expands the clinical, histologic, and molecular spectrum of local ALK-positive histiocytosis. Since ALK-positive histiocytosis associated with a significant inflammatory component can pose considerable diagnostic challenges, increased awareness of this peculiar variant of ALK-positive histiocytosis is essential to minimize the risk of misdiagnosis.

Mimicking Anti-Viruses with Machine Learning and Entropy Profiles

The quality of anti-virus software relies on simple patterns extracted from binary files. Although these patterns have proven to work on detecting the specifics of software, they are extremely sensitive to concealment strategies, such as polymorphism or metamorphism. These limitations also make anti-virus software predictable, creating a security breach. Any black hat with enough information about the anti-virus behaviour can make its own copy of the software, without any access to the original implementation or database. In this work, we show how this is indeed possible by combining entropy patterns with classification algorithms. Our results, applied to 57 different anti-virus engines, show that we can mimic their behaviour with an accuracy close to 98% in the best case and 75% in the worst, applied on Windows’ disk resident malware.

A case of giant intracranial tuberculoma in an infant: clinical and radiologic pitfalls

Intracranial tuberculoma in infants are a rare occurrence. We report a 7-month-old male infant presenting to our tertiary care referral center with complaints of global developmental delay and right hemiparesis for 3 months. Radiologic imaging was suggestive of large left frontoinsular space-occupying lesion with initial differential of primitive neuroectodermal tumor or desmoplastic infantile ganglioglioma. Considering the clinicoradiologic findings and no history suggestive of immunodeficiency or contact with tuberculosis, surgical decompression was done. Final histopathology revealed multiple epithelioid granulomas suggestive of tubercular etiology or intracranial Langerhans cell histiocytosis. He was started on antitubercular therapy after ruling out Langerhans cell histiocytosis using CD1a and Langerin immunohistochemistry staining. Interpretation of tuberculous etiology in infants can be challenging for clinicians, radiologists, and pathologists. A high index of suspicion is necessary to diagnose such lesions, predominantly in endemic regions.

Tuberculosis cervical lymphadenopathy mimics lateral neck metastasis from papillary thyroid carcinoma

BACKGROUND

Tuberculosis (TB) lymphadenitis is a frequent cause of lymphadenopathy in areas in which TB is endemic. Cervical lymphadenopathy in TB can mimic lateral neck metastasis (LNM) from papillary thyroid carcinoma (PTC). This study evaluated the clinicopathological features of patients with PTC and TB lateral neck lymphadenopathy.

METHODS

Of the 9098 thyroid cancer patients who underwent thyroid cancer surgery at the Thyroid Cancer Center of Gangnam Severance Hospital between January 2009 and April 2013, 28 had PTC and showed TB lymphadenopathy of the lateral neck node. The clinicopathological features of these 28 patients were evaluated.

RESULTS

Preoperatively, all 28 patients were diagnosed with PTC and showed cervical lymphadenopathy. All had radiological characteristics suspicious of metastasis in lateral neck nodes. Based upon the results from intraoperative frozen sections, lymph node dissection (LND) was not performed on 19 patients. Seven of eight patients who underwent LND had metastasis combined with tuberculous lymphadenopathy, with the remaining patient negative for LNM.

CONCLUSIONS

Intraoperative sampling and frozen sectioning of lymph nodes suspicious of metastasis can help avoid unnecessary LND for tuberculous lymphadenopathy.

Case of intestinal tuberculosis mimicking Crohn's disease

BACKGROUND

Intestinal tuberculosis can closely mimic Crohn's disease and colon cancer. Presented here is a case of intestinal tuberculosis that closely mimicked both.

CASE REPORT

A 23 year old Hispanic female presented with several months of weight loss, recurrent fever, and emesis. The patient did not have pulmonary symptoms or radiographic evidence of tuberculosis. Colonoscopy evaluation with biopsy of the affected bowel segments were thought to be consistent with either colon cancer or Crohn's Disease. Acid fast bacilli staining and histological analysis did not display evidence of tuberculosis on two separate occasions. The patient developed colonic obstruction acutely during the course of treatment requiring resection of the affected bowel segment. Acid fast staining of the resected lymph nodes was positive and submucosal caseating granulomas were identified histologically, consistent with intestinal tuberculosis.

CONCLUSIONS

Intestinal tuberculosis remains a diagnostic challenge. Consideration of the disease should be maintained in equivocal cases.

Subungual Amelanotic Melanoma Masquerading as Onychomycosis

Subungual amelanotic melanoma is rare. In addition, amelanotic melanoma can mimic non-melanocytic tumors. A 67-year-old woman had a four-year history of dystrophy of the left fourth fingernail. Periodic acid-Schiff staining of the nail plate demonstrated fungal hyphae, establishing a diagnosis of tinea unguium. The nail plate subsequently detached and the underlying nail bed showed a red, friable mass that was biopsied and confirmed a diagnosis of melanoma. In conclusion, additional morphologic change of a persistent nail dystrophy-even with a biopsy-confirmed diagnosis of onychomycosis-may require consideration for repeat evaluation, including a biopsy, to exclude the possibility of a subungual malignant tumor.

CT and MRI Findings of Autoimmune Polymorph Bifocal Pancreatitis Mimicking Pancreatic Adenocarcinoma: A Case Report and Review of the Literature

Autoimmune pancreatitis is a rare type of chronic pancreatitis. It is supposed to be a pancreatic manifestation of an immune-complex modulated systemic disorder. In contrast, pancreatic adenocarcinoma is the most frequent malignant neoplasm of the pancreas. Within the rare type of focal autoimmune pancreatitis, only few presentations with multifocal pancreatic lesions have been described. Herein we report a case of a 58-year-old patient with autoimmune pancreatitis presenting with bifocal manifestations of the pancreatic head and tail, mimicking pancreatic adenocarcinoma clinically, on computed tomography and magnetic resonance imaging. Typical imaging findings of autoimmune pancreatitis are compared with typical findings in pancreatic carcinoma. The diagnostic dilemma of differentiating between both entities is discussed. A review of the present literature regarding multifocal presence of autoimmune pancreatitis is performed.

Adenoid cystic carcinoma of the upper airway mimicking a thyroid tumor: A case report

Adenoid cystic carcinoma (ACC) is a rare malignant tumor, reportedly representing <1% of all head and neck cancers. There have been few reported cases of ACC of the upper airway presenting as a midline mass. This is the case report of a 47-year-old female patient who presented with such a midline neck mass. The mass was approached and investigated as a thyroid mass, but was ultimately found to be a tracheal tumor with thyroid invasion. We herein discuss in detail the patient history, investigation and treatment.

Idiopathic Granulomatous Lobular Mastitis: An Imitation of Breast Carcinoma

Since idiopathic granulomatous lobular mastitis, also known as idiopathic granulomatous mastitis or granulomatous lobulitis, was first described by Kessler and Wolloch in 1972, no consensus on the ideal and definitive treatment for this phenomenon has been reached thus far. Idiopathic granulomatous lobular mastitis mostly frequently observed in women of childbearing age within a few years of pregnancy with a higher incidence in patients of Hispanic, Native American, Middle Eastern, and African descent. This entity, per se, is a rare, benign, chronic inflammatory breast condition of unknown aetiology mimicking two common breast disorders. The first is breast inflammations or infection, such as cystic neutrophilic granulomatous mastitis; granulomatous mastitis due to Corynebacterium;other infections with granulomas, mycobacteria, fungi, cat scratch disease, and Brucella; granulomatosis with polyangiitis (Wegener's granulomatosis); sarcoidosis; and squamous metaplasia of lactiferous ducts. The second is breast carcinoma in some challenging cases. Of note, no consensus, per se, has been declared on its therapeutic management. The following vignette case described in this report involves idiopathic granulomatous lobular mastitis imitating breast carcinoma. It is important to note that, the aetiology of idiopathic granulomatous lobular mastitis is unknown, its diagnosis is difficult, and physicians should be vigilant and aware of this condition in order of abstaining from an overtreatment for malignancy or overlooking a true malignancy.

Mimicked Periosteum Layer Based on Deposited Particle Silk Fibroin Membrane for Osteogenesis and Guided Bone Regeneration in Alveolar Cleft Surgery: Formation and in Vitro Testing

An alveolar cleft is a critical tissue defect often treated with surgery. In this research, the mimicked periosteum layer based on deposited silk fibroin membrane was fabricated for guided bone regeneration in alveolar cleft surgery. The deposited silk fibroin particle membranes were fabricated by spray-drying with different concentrations of silk fibroin (v/v): 0.5% silk fibroin (0.5% SFM), 1% silk fibroin (1% SFM), 2% silk fibroin (2% SFM), and 1% silk fibroin film (1% SFF) as the control. The membranes were then characterized and the molecular organization, structure, and morphology were observed with FT-IR, DSC, and SEM. Their physical properties, mechanical properties, swelling, and degradation were tested. The membranes were cultured with osteoblast cells and their biological performance, cell viability and proliferation, total protein, ALP activity, and calcium deposition were evaluated. The results demonstrated that the membranes showed molecular transformation of random coils to beta sheets and stable structures. The membranes had a porous layer. Furthermore, they had more stress and strain, swelling, and degradation than the film. They had more unique cell viability and proliferation, total protein, ALP activity, calcium deposition than the film. The results of the study indicated that 1% SFM is promising for guided bone regeneration for alveolar cleft surgery.

The bone-mimicking effect of calcium phosphate on composite chitosan scaffolds in maxillofacial bone tissue engineering

This research explored a new trend in biomaterials science. The bone-mimicking effect of calcium phosphate on chitosan composite scaffolds was evaluated. Chitosan with 2% calcium phosphate was found to have suitable bone-mimicking performance for maxillofacial bone tissue engineering.

Asymptomatic Papulo-nodules Localized to One Finger

Subcutaneous or deep granuloma annulare is a benign asymptomatic condition characterized by firm asymptomatic nodules in deep subcutaneous tissues that may be associated with intradermal lesions. A 53-year-old female presented with asymptomatic skin-colored, firm nodules over the right ring finger. Histopathology revealed a palisading granuloma with central degenerated collagen and mucin deposition in the dermis suggestive of granuloma annulare. Isolated and unilateral involvement of a single digit with clusters of nodules of subcutaneous granuloma annulare (GA) in an adult is rare and differentiation from its simulator rheumatoid nodule is essential.

Biological Children Versus Stepchildren: Interorganizational Learning Processes of Spinoff and Nonspinoff Suppliers

Interorganizational scholars have long thought about how firms learn through buyer relationships. However, it is not clear whether dyadic learning gains are susceptible to imitation or are only inherited and whether these gains decay over time or are of an enduring nature. In this paper, I import ideas from the organizational imprinting literature into the interorganizational literature and apply the knowledge-based and learning views of the firm to examine how suppliers with differing initial endowments learn to work together with a buyer. The findings from an inductive multiple case study of spinoff and nonspinoff suppliers of an automotive manufacturer parent in Turkey reveal the following three learning mechanisms: informal relationships and social capital, transfer of routines, and shared identity. Although nonspinoff suppliers also exhibit evidence of several learning processes to a certain extent, spinoff suppliers' deeper relationship, in particular their shared identity, with their parent based on their direct parental heritage tends to be more difficult for them to copy. No matter how hard nonspinoff suppliers try, they have "one hand tied behind their back," they remain stepchildren, and they never truly become a biological child. By providing a novel setting and a rich set of qualitative data on the learning behaviors of these two types of suppliers, this study teases apart the knowledge and resources that can be "learned from external sources" versus those that can "only be inherited."

Hypertrophic Lichen Planus Mimicking Verrucous Lupus Erythematosus

Lichen planus is an inflammatory skin condition that can affect the hair, mucous membranes, nails, and skin. Cutaneous lichen planus typically presents as papules that are planar, polygonal, pruritic, and purple. Subtypes of lichen planus include actinic, annular, atrophic, eruptive, follicular, hypertrophic, inverse, linear, palmoplantar, pemphigoides, pigmentosus, ulcerative, vesiculobullous, and vulvovaginal. The various clinical presentations of lichen planus can mimic other dermatologic conditions. A 63-year-old woman, who presented with pruritic, hyperkeratotic plaques on the lower legs of two years duration, is described; her lesions were morphologically suggestive of verrucous lupus erythematosus. However, an examination also revealed purple papules on the wrists and white, reticulated patches on the bilateral buccal mucosa. Biopsies demonstrated lichenoid dermatitis while laboratory studies for systemic lupus erythematosus were negative. A correlation of the clinical presentation, pathology, and laboratory studies established a diagnosis of hypertrophic lichen planus. The clinical mimickers of hypertrophic lichen planus are reviewed and the therapeutic treatments for this condition discussed.

A rare syndrome mimicking scleroderma: Werner syndrome

Werner syndrome (WS), also known as adult progeria, is a premature ageing syndrome that can manifest itself with grey hair, hair loss, diabetes mellitus, hyperlipidaemia, hypertension, skin disorders, ocular cataracts, myocardial infarction, osteoporosis, and stroke, especially after puberty. Physical examination findings similar to systemic sclerosis may be seen. Therefore, it may mimic this disease as misleading. A 43-year-old female patient was admitted to our clinic with a pre-diagnosis of systemic sclerosis complaint of skin hardening up to the ankle. In the first physical examination, there were wrinkles and thinning of the lip, suggesting systemic sclerosis in the facial appearance. On her capillaroscopy, there was tortuosity and an old focus of microhemorrhage. She had a history of diabetes mellitus and chronic osteomyelitis. When all symptoms, clinical findings, and antibody results were combined, it was thought that the patient might have WS. WS was diagnosed with homozygous c.2221 C>P p.R741*(rs763089663) positive in genetic analysis. It is known that WS creates a predisposition to malignancies, and most patients die secondary to malignancies. Therefore, early diagnosis becomes essential. Early diagnosis is of vital importance both to prevent complications and to delay treatment. In particular, systemic sclerosis-like findings of this syndrome may cause delays in diagnosis. For this reason, small clues suggesting WS in the clinic should be well known and well defined.

Tissue scaffolds mimicking hierarchical bone morphology as biomaterials for oral maxillofacial surgery with augmentation: structure, properties, and performance evaluation forin vitrotesting

In this study, tissue scaffolds mimicking hierarchical morphology are constructed and proposed for bone augmentation. The scaffolds are fabricated using lyophilization, before coating them with collagen (Col). Subsequently, the Col-coated scaffolds undergo a second lyophilization, followed by silk fibroin (SF) coating, and a third lyophilization. Thereafter, the scaffolds are divided into six groups with varying ratios of Col to SF: Col/SF = 7:3, 5:5, 3:7, 10:0, and 0:10, with an SF scaffold serving as the control group. The scaffold morphology is examined using a scanning electron microscope, while molecular and structural formations are characterized by Fourier transform infrared spectrometer and differential scanning calorimeter, respectively. Physical and mechanical properties including swelling and compression are tested. Biological functions are assessed throughin vitroosteoblast cell culturing. Biomarkers indicative of bone formation-cell viability and proliferation, alkaline phosphatase activity, and calcium content-are analyzed. Results demonstrate that scaffolds coated with Col and SF exhibit sub-porous formations within the main pore. The molecular formation reveals interactions between the hydrophilic groups of Col and SF. The scaffold structure contains bound water and SF formation gets disrupted by Col. Physical and mechanical properties are influenced by the Col/SF ratio and morphology due to coating. The biological functions of scaffolds with Col and SF coating show enhanced potential for promoting bone tissue formation, particularly the Col/SF (7:3) ratio, which is most suitable for bone augmentation in small defect areas.

Contiguous Multilevel Vertebral Metastasis in Carcinoma Breast Mimicking Spondylodiscitis

A 59-year old female presented with a lump in the right breast for 6 months. She developed progressively increasing backache for 3 months. Magnetic resonance imaging spine was suggestive of hypointense heterogeneous signal intensity in multiple dorsal vertebrae (D3–D8) and suggestive of Pott's spine. Sonomammography suggested a lesion with irregular margin in the retro-areolar region. Fine-needle aspiration cytology was infiltrating duct carcinoma. Fluorodeoxyglucose (FDG) positron-emission tomography–computed tomography revealed mass in the right breast with axillary lymph node. FDG-avid lytic destructive contiguous lesion was noted in mid-dorsal vertebrae. Apart from it, FDG-avid lytic lesion was also noted in the right iliac bone. The patient underwent vertebral lesion biopsy consistent with metastatic breast carcinoma. This case report demonstrates rare contiguous involvement of multiple vertebrae masquerading Pott's spine.

A Perplexing Case of Bladder Mass Biopsy-Proven Neurosarcoidosis

Sarcoidosis is a multi-organ systemic disease that presents with several clinical manifestations, and patients can develop neurologic complications. Neurosarcoidosis may be life-threatening; therefore, early recognition and treatment are key. Here, we present a case of a 55-year-old African American male who presented with a complaint of dizziness and left-sided weakness; he ultimately received a diagnosis of neurosarcoidosis after elaborate radiographic investigations and bladder mass biopsy. Neurosarcoidosis remains a diagnostic dilemma as it can clinically and radiographically mimic multiple conditions including multiple sclerosis, central nervous system lymphoma, multiple myeloma, and progressive multifocal leukoencephalopathy.

Mimicking bone remodeling scaffolds of polyvinylalcohol/silk fibroin with phytoactive compound of soy protein isolate as surgical supporting biomaterials for tissue formation at defect area in osteoporosis; characterization, morphology, andin-vitrotesting

Mimicking bone remodeling scaffolds were developed as supportive biomaterials to promote tissue formation at defect sites in osteoporosis. Scaffolds made of polyvinyl alcohol (PVA) were mixed with varying weight ratios of silk fibroin (SF) and a phytoactive compound-based soy protein isolate (SPI); PVA30SF, PVA20SF10SPI, PVA15SF15SPI, PVA10SF20SPI, PVA30SPI. PVA was used as control. These components were mixed into aqueous solution and crosslinking with EDC before freeze thawing and freeze drying, respectively. Then, the scaffolds were characterized at the molecular level using Fourier transform infrared spectroscopy and their morphology was observed using scanning electron microscopy. Physical properties including swelling and degradation were tested, as well as mechanical properties like stress-strain behavior and modulus. The biological performance of the scaffolds was evaluated through osteoblast cell culturing, assessing cell viability, proliferation, alkaline phosphatase (ALP) activity, calcium content, and calcium deposition. The results demonstrate that the scaffolds with both SF and SPI had greater molecular mobility of -OH, amide I, II, and III groups, compared to the scaffold with only SF or SPI. These scaffolds also displayed larger pore sizes. Scaffolds with both SF and SPI showed higher swelling and degradation rates than those with only SF or SPI. Additionally, they exhibited better cell viability and calcium deposition, along with increased cell proliferation, ALP activity, and calcium content. Notably, the scaffold with a higher amount of SPI, PVA10SF20SPI, exhibited the most suitable performance for enhancing cell response, thereby promoting bone formation. This scaffold is proposed as a supportive biomaterial to be incorporated with plates and screws for bone fixation at defect sites in osteoporosis.