Biodegradable polymeric matrices for bioartificial implants

2002 ◽  
Vol 25 (5) ◽  
pp. 434-441 ◽  
Author(s):  
E. Pişkin
Keyword(s):  
Disease Transmission ◽  
Mammalian Cells ◽  
Donor Site ◽  
Embryonic Stem ◽  
Donor Site Morbidity ◽  
New Approach ◽  
Synthetic Materials ◽  
Time Period ◽  
Risk Of Disease ◽  
Closed Systems

Biomaterials made of polymers, metals or their alloys, ceramics and their composites, are used as implants to restore or to replace the damaged soft and hard tissue/organ functions for an intended time period. Biomaterials made of synthetic materials are very simple materials compared to their natural counterparts, they only replace very simple functions of the damaged tissue during healing. Natural tissues have been used for both soft and hard repair and replacement, but they do have serious limitations such as: shortage of donor tissue, donor site morbidity, unpredictable resorption characteristics, immunogenic response, risk of disease transmission, and ethical limitations. Tissue engineering is a relatively new approach, in which healthy mammalian cells are used with supporting matrices, usually made of either natural or synthetic polymers as composite bioartificial implants. Primary cells, especially embryonic stem cells, cell lines, hybridomas, genetically modified cells are considered as potential sources for this application. Both closed and open matrices are used as support matrices. Nondegradable and biocompatible microcapsules and hollow fibers are utilized in closed systems, especially for immunoprotection of the transplanted cells. Biodegradable polymers, both natural and synthetic are used in the preparation of bioartificial implants carrying only autogenic cells.

Augmentation of Oral Tissues in Rabbit Using Autogenous Fat

1995 ◽  
Vol 32 (1) ◽  
pp. 1-6 ◽  
Author(s):  
John W. Canady ◽  
Sue Ann Thompson ◽  
Jerald B. Moon ◽  
Richard L. Glowacki
Keyword(s):  
Oral Cavity ◽  
Speech Therapy ◽  
Donor Site ◽  
Posterior Pharyngeal Wall ◽  
Donor Site Morbidity ◽  
Speech Disorders ◽  
Pharyngeal Wall ◽  
Synthetic Materials ◽  
Velopharyngeal Incompetence ◽  
The Stability

Patients with mild velopharyngeal incompetence (VPI) may have speech disorders, which are not sufficiently severe to warrant extensive surgical intervention, yet may not be amenable to correction by speech therapy alone. Augmentation of the posterior pharyngeal wall to aid in closure of the velopharyngeal sphincter may be beneficial in establishing better speech patterns, especially when combined with speech therapy. A variety of materials and techniques have been used in the past for this purpose. In this setting, autogenous fat may be transplanted without the risks incurred by augmentation with synthetic materials and involves very little donor site morbidity. The literature is somewhat contradictory, however, regarding the stability of the augmentation achieved using autogenous fat and there are no histologic studies describing the fate of fat injected into tissues of the oral cavity. Prior to introduction of this technique into clinical practice, this study was designed to investigate the fate of autogenous fat injected submucosally in the oropharyngeal region. Autogenous fat was injected into the anterior soft palate using the rabbit as a model. Histologic and gross inspections were performed at 2 days, 1, 2, and 4 weeks after injections. At the end of 4 weeks, at least 50% of the injection sites had visible evidence of augmentation, and 90% had histologic evidence of submucosal fat. In some instances most of the fat was resorbed; however, there were no instances of clinical infection or necrosis of the injection site. We conclude that submucosal injection of autogenous fat is a feasible alternative to using synthetic or other biologic materials for augmentation in the oral cavity.

Case Series: Use of Coralline Hydroxyapatite Graft In Faciomaxillary Surgery

2021 ◽  
Author(s):  
Gordon Slater
Keyword(s):  
Bone Graft ◽  
Disease Transmission ◽  
Bone Ingrowth ◽  
Donor Site ◽  
Case Series ◽  
Bone Graft Substitute ◽  
Donor Site Morbidity ◽  
Coralline Hydroxyapatite ◽  
Important Solution ◽  
The Ideal

Bone grafting represents an important solution for defects in maxillofacial and orthopaedic surgeries. Ideal properties of a bone graft allow proper integration, enabling cosmetic appeal and mechanical functionality. Whilst current autograft, allograft and xenograft applications do exist and are regularly used clinically, they are associated with numerous solutions, such as availability, disease transmission and donor site morbidity. Synthetic and naturally sourced solutions can avoid these issues, whilst maintaining the ideal bone integrative properties of their autograft counterparts. This case series aims to identify the effectiveness of a natural bone graft substitute, coralline hydroxyapatite, in maxillofacial applications, and demonstrate that coralline hydroxyapatite encourages bone ingrowth for dental defects.

Low Donor Site Morbidity Associated With Tricortical Calcaneal Bone Graft

2021 ◽  
pp. 107110072110326
Author(s):  
Gabriel Ferraz Ferreira ◽  
João Henrique Almeida Costa ◽  
Giancarlo Domingues ◽  
João Paulo Bacellar Costa Lima ◽  
José Antônio Veiga Sanhudo ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Donor Site ◽  
Achilles Tendon Rupture ◽  
Case Series ◽  
Donor Site Morbidity ◽  
Oral Antibiotic ◽  
Level Of Evidence ◽  
Superficial Infection ◽  
Alternative Source ◽  
Calcaneal Tuberosity

Background: Autologous grafting is widely used in orthopedic surgery because of its high osteogenic capacity, immunologic compatibility, for the absence of risk of disease transmission, and for not requiring a bone bank. The posterior-superior calcaneal tuberosity is an option for obtaining a cortical and cancellous structural bone. This study aims to describe the operative technique and complications observed at the donor site of the posterior-superior calcaneal tuberosity. Methods: Patients who underwent graft harvesting from the posterior-superior calcaneal tuberosity were retrospectively evaluated by pain outcomes, imaging tests, and intra- and postoperative complications. Results: Twenty patients with a median age of 69 years (range 48-77) and follow-up of 16 months (12-26) were assessed. Median postoperative pain at the donor site was 0 (0-6), with 2 patients reporting persistent local pain. No case of Achilles tendon rupture or intra- or postoperative calcaneal fracture were identified. One patient developed a superficial infection that was quickly resolved using oral antibiotic therapy. Conclusion: The posterior-superior calcaneal tuberosity is an alternative source of autologous graft with low donor site morbidity. Level of Evidence Level IV, case series.

scholarly journals Seminal fluid of honeybees contains multiple mechanisms to combat infections of the sexually transmitted pathogen Nosema apis

2016 ◽  
Vol 283 (1823) ◽  
pp. 20151785 ◽  
Author(s):  
Yan Peng ◽  
Julia Grassl ◽  
A. Harvey Millar ◽  
Boris Baer
Keyword(s):  
Disease Transmission ◽  
Protein Fraction ◽  
Fungal Pathogen ◽  
Seminal Fluid ◽  
Nosema Apis ◽  
High Quality ◽  
Sexually Transmitted ◽  
Risk Of Disease ◽  
Closed Systems ◽  
Defence Proteins

The societies of ants, bees and wasps are genetically closed systems where queens only mate during a brief mating episode prior to their eusocial life and males therefore provide queens with a lifetime supply of high-quality sperm. These ejaculates also contain a number of defence proteins that have been detected in the seminal fluid but their function and efficiency have never been investigated in great detail. Here, we used the honeybee Apis mellifera and quantified whether seminal fluid is able to combat infections of the fungal pathogen Nosema apis , a widespread honeybee parasite that is also sexually transmitted. We provide the first empirical evidence that seminal fluid has a remarkable antimicrobial activity against N. apis spores and that antimicrobial seminal fluid components kill spores in multiple ways. The protein fraction of seminal fluid induces extracellular spore germination, which disrupts the life cycle of N. apis , whereas the non-protein fraction of seminal fluid induces a direct viability loss of intact spores. We conclude that males provide their ejaculates with efficient antimicrobial molecules that are able to kill N. apis spores and thereby reduce the risk of disease transmission during mating. Our findings could be of broader significance to master honeybee diseases in managed honeybee stock in the future.

Strategy for Tissue Engineering of Osteochondral Constructs

2002 ◽  
Author(s):  
Erica Takai ◽  
X. Edward Guo ◽  
Helen H. Lu ◽  
Michelle A. LeRoux ◽  
Priya Raina ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Disease Transmission ◽  
Articular Surface ◽  
Donor Site ◽  
Focal Lesions ◽  
The Poor ◽  
Donor Site Pain ◽  
Cell Tissue ◽  
Risk Of Disease ◽  
Total Knee

Damage to articular cartilage is a common condition affecting the joints of millions of people. This is a major problem considering the poor regenerative capacity of adult articular cartilage and the disability and pain that accompanies these injuries [13]. There exists a range of options that have been applied in clinical practice, with variable degrees of success, for repair of focal lesions and damage of the articular surface, including tissue adhesives [1,6,11,12,18], enzymatic treatments [8] and laser solder welding [21], autograft cell/tissue transfer via osteoperiosteal grafts [17], osteochondral grafts (mosaicplasty) [10] and Carticel [4,5]. The poor healing capacity of articular cartilage [13], potential for donor site pain and morbidity in autograft procedures, risk of disease transmission in allograft procedures, and the limited longevity of arthroplasty systems (i.e., ∼15 years for a total knee arthroplasty), has generated considerable research efforts to develop cell-based therapies for articular cartilage repair and replacement.

scholarly journals Investigation Into the Optimal Number of Intercostal Nerve Transfers for Musculocutaneous Nerve Reinnervation: A Systematic Review

Hand ◽  
2017 ◽  
Vol 13 (6) ◽  
pp. 621-626 ◽  
Author(s):  
Hyuma A. Leland ◽  
Beina Azadgoli ◽  
Daniel J. Gould ◽  
Mitchel Seruya
Keyword(s):  
Systematic Review ◽  
Brachial Plexus ◽  
Donor Site ◽  
Elbow Flexion ◽  
Donor Site Morbidity ◽  
Intercostal Nerve ◽  
Optimal Number ◽  
Musculocutaneous Nerve ◽  
Nerve Transfers ◽  
Meta Analyses

Background: The purpose of this study was to systematically review outcomes following intercostal nerve (ICN) transfer for restoration of elbow flexion, with a focus on identifying the optimal number of nerve transfers. Methods: A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines to identify studies describing ICN transfers to the musculocutaneous nerve (MCN) for traumatic brachial plexus injuries in patients 16 years or older. Demographics were recorded, including age, time to operation, and level of brachial plexus injury. Muscle strength was scored based upon the British Medical Research Council scale. Results: Twelve studies met inclusion criteria for a total of 196 patients. Either 2 (n = 113), 3 (n = 69), or 4 (n = 11) ICNs were transferred to the MCN in each patient. The groups were similar with regard to patient demographics. Elbow flexion ≥M3 was achieved in 71.3% (95% confidence interval [CI], 61.1%-79.7%) of patients with 2 ICNs, 67.7% (95% CI, 55.3%-78.0%) of patients with 3 ICNs, and 77.0% (95% CI, 44.9%-93.2%) of patients with 4 ICNs ( P = .79). Elbow flexion ≥M4 was achieved in 51.1% (95% CI, 37.4%-64.6%) of patients with 2 ICNs, 42.1% (95% CI, 29.5%-55.9%) of patients with 3 ICNs, and 48.4% (95% CI, 19.2%-78.8%) of patients with 4 ICNs ( P = .66). Conclusions: Previous reports have described 2.5 times increased morbidity with each additional ICN harvest. Based on the equivalent strength of elbow flexion irrespective of the number of nerves transferred, 2 ICNs are recommended to the MCN to avoid further donor-site morbidity.

scholarly journals Livestock movement informs the risk of disease spread in traditional production systems in East Africa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Divine Ekwem ◽  
Thomas A. Morrison ◽  
Richard Reeve ◽  
Jessica Enright ◽  
Joram Buza ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Production Systems ◽  
Control Strategies ◽  
Herd Size ◽  
Transmission Risk ◽  
Disease Spread ◽  
Transmission Potential ◽  
Spatial And Temporal Scales ◽  
Transmission Distance ◽  
Risk Of Disease

AbstractIn Africa, livestock are important to local and national economies, but their productivity is constrained by infectious diseases. Comprehensive information on livestock movements and contacts is required to devise appropriate disease control strategies; yet, understanding contact risk in systems where herds mix extensively, and where different pathogens can be transmitted at different spatial and temporal scales, remains a major challenge. We deployed Global Positioning System collars on cattle in 52 herds in a traditional agropastoral system in western Serengeti, Tanzania, to understand fine-scale movements and between-herd contacts, and to identify locations of greatest interaction between herds. We examined contact across spatiotemporal scales relevant to different disease transmission scenarios. Daily cattle movements increased with herd size and rainfall. Generally, contact between herds was greatest away from households, during periods with low rainfall and in locations close to dipping points. We demonstrate how movements and contacts affect the risk of disease spread. For example, transmission risk is relatively sensitive to the survival time of different pathogens in the environment, and less sensitive to transmission distance, at least over the range of the spatiotemporal definitions of contacts that we explored. We identify times and locations of greatest disease transmission potential and that could be targeted through tailored control strategies.

scholarly journals Use of Gracile and semi-tendinosus tendons (GRAST) for the reconstruction of irreparable rotator cuff tears

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Marie Protais ◽  
Maxime Laurent-Perrot ◽  
Mickaël Artuso ◽  
M. Christian Moody ◽  
Alain Sautet ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Donor Site ◽  
Anatomical Study ◽  
Donor Site Morbidity ◽  
Rotator Cuff Tears ◽  
Subacromial Space ◽  
Greater Tuberosity ◽  
Working Zone ◽  
Superior Capsular Reconstruction

Abstract Background Irreparable rotator cuff tears are common and difficult to treat. Techniques for “filling the loss of substance” require fixation to the rotator cuff stump (tendon augmentation) or to the glenoid (superior capsular reconstruction), which are complicated by the narrow working zone of the subacromial space. The main objective of this study was to determine whether a braided graft of gracilis (GR) and semitendinosus (ST) could fill a loss of tendon substance from an irreparable rupture of the supra- and infraspinatus, by fixing the graft to the greater tuberosity and the spine of the scapula. Methods This was a cadaveric study with the use of ten specimens. The GRA and ST tendons were harvested, braided and reinforced with suture. An experimental tear of the supraspinatus (SS) and upper infraspinatus (IS) retracted at the glenoid was made. The GRAST transplant was positioned over the tear. The transplant was attached to the greater tuberosity by two anchors and then attached to the medial third of the scapular spine by trans-osseous stitching. The percentage of filling obtained was then measured and passive mobility of the shoulder was assessed. We proceeded to the same technique under arthroscopy for a 73 years old patient whom we treated for a painful shoulder with irreparable cuff tear. We inserted a GRAST graft using arthroscopy. Results The Braided-GRAST allowed a 100% filling of the loss of tendon substance. Mobility was complete in all cases. Conclusion This technique simplifies the medial fixation and restores the musculo-tendinous chain where current grafting techniques only fill a tendinous defect. The transplant could have a subacromial “spacer” effect and lower the humeral head. The donor site morbidity and the fate of the transplant in-vivo are two limits to be discussed. This anatomical study paves the way for clinical experimentation.

scholarly journals Suprafascial Free Flaps: Classification and Comprehensive Review of the Literature

2021 ◽  
Vol 6 ◽  
pp. 247275122110205
Author(s):  
Sebastian Rios ◽  
María Isabel Falguera-Uceda ◽  
Alicia Dean ◽  
Susana Heredero
Keyword(s):  
Survival Rate ◽  
Preoperative Planning ◽  
Donor Site ◽  
Free Flaps ◽  
Donor Site Morbidity ◽  
Anterolateral Thigh Flap ◽  
Cochrane Library ◽  
Review Of The Literature ◽  
Comprehensive Review ◽  
Search Terms

Study Design: Suprafascial free flaps have become common place in reconstructive surgery units. Nomenclature related to these flaps has not been uniform throughout the scientific literature, especially in regard to planes of dissection. This study is designed as a comprehensive review of the literature. Objectives: Our study highlights which flaps are used most frequently, their main indications, their survival rate, and how they have evolved in the last few decades as innovations have been introduced. Methods: A review of the literature was performed using keywords and Medical Subject Headings search terms. PubMed, Embase, and Cochrane Library were searched using the appropriate search terms. Data collected from each study included flap type, dissection plane, preoperative planning, area of reconstruction, as well as complications, donor-site morbidity and survival rate. Results: Seven hundred and fifty-five studies were found based on the search criteria. After full-text screening for inclusion and exclusion criteria 34 studies were included. A total of 1332 patients were comprised in these studies. The most common types of flaps used were superficial circumflex iliac perforator flap (SCIP), anterolateral thigh flap (ALT), and radial forearm flap. The most common areas of reconstruction were head & neck and limbs. There was no significant difference in survival rates between flaps that were raised in different planes of dissection. Conclusions: Based on the author’s review of the literature, suprafascial flaps are reliable, they have low donor site morbidity, and there is a wide selection available for harvest. The use of new technologies for preoperative planning, such as CT-Angiography and UHF ultrasound, have contributed to have more predictable results. We propose a standardized classification for these flaps, in order to create a uniform nomenclature for future reference.

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