Four-Dimensional (4D) Printing of Dynamic Foods-Definitions, Considerations, and Current Scientific Status.

Since its conception, the application of 3D printing in the structuring of food materials has been focused on the processing of novel material formulations and customized textures for innovative food applications, such as personalized nutrition and full sensory design. The continuous evolution of the used methods, approaches, and materials has created a solid foundation for technology to process dynamic food structures. Four-dimensional food printing is an extension of 3D printing where food structures are designed and printed to perform time-dependent changes activated by internal or external stimuli. In 4D food printing, structures are engineered through material tailoring and custom designs to achieve a transformation from one configuration to another. Different engineered 4D behaviors include stimulated color change, shape morphing, and biological growth. As 4D food printing is considered an emerging application, imperatively, this article proposes new considerations and definitions in 4D food printing. Moreover, this article presents an overview of 4D food printing within the current scientific progress, status, and approaches.

Multi-scale dough adhesion analysis: Relation between laboratory scale, pilot scale and human sensory.

Undesired dough adhesion is still a challenge during the production of baked goods. There are various methods for determining the adhesive texture properties of dough. In the majority of scientific papers, dough stickiness is measured analytically by the force-distance recording of dough detachment. In this study, we describe a new multi-scale approach to compare dough adhesion phenomena in a laboratory, pilot sale and human sensory assessment. In it, the adhesive material properties of dough were investigated using a pilot scale toppling device representing dough adhesion behavior in the production process, in the laboratory by texture analysis with the Chen-Hoseney method and furthermore with a new, implemented non-oral human sensory analysis. To simulate different dough adhesion behavior, the dough mechanical and adhesion properties were varied by applying dough-modifying enzymes and different dough storage times. The structural changes in the different wheat dough system were compared by rheological characterization. By characterizing the different adhesion phenomena of the doughs, the sample with bacterial xylanase showed the highest values after 80 min of storage time in all three methods. Correlation analysis revealed a strong relationship between the detachment time (pilot scale) and human sensory assessment attributes (Force R = 0.81, Time R = 0.87, Distance R = 0.92, Stickiness R = 0.80) after 80 min of storage time. Even though human sensory assessment showed limits in the detectability of differences in dough adhesion behavior compared to the Chen-Hoseney method, it was better suited to predict machinability.

Texture modulation of starch-based closed-cell foams using 3D printing: Deformation behavior beyond the elastic regime.

3-dimensional printing is a novel processing method used for the design and manipulation of food textures. The systematic characterization and modulation of 3D printed food textures is imperative for the future design of sensory profiles using additive manufacturing. For 3D printed closed-cell food foams, the clarification of the deformation behavior in relation to design parameters is of interest for the processing of customized food textures. For this reason, we studied the deformation behavior of 3D printed and thermally stabilized closed-cell starch-based foams beyond the elastic regime. Periodic spherical bubble configurations at different porosity levels were used to modulate the deformation behavior of the printed foams. From a processing perspective, the integration of in-line thermal stabilization was used to eliminate post-processing and to control the moisture content of the starch-based system. Compression analysis combined with FEM simulations were performed to characterize the strain rate dependency of textural properties, the stress relaxation, and the foam's stress-strain behavior with respect to the design porosity and bubble distribution. Results showed that the stress relaxation is solely dependent on cell wall properties while different stress-strain regimes showed distinct dependencies on design parameters such as bubble size and distribution. Consequently, the precise control of the large deformation behavior of foods using 3D printing is challenging due to the superposition of structural and geometrical dependencies. Finally, through the presented approach, the structure-deformation relations of 3D printed closed-cell food structures are adequately described.

The helpful twin: Skin graft donation in a challenging burn case.

OBJECTIVES: This is the first report of a successful skin grafting between monozygotic twins in the United Kingdom (UK). We discuss the process of assessing the suitability of the patients for the procedure, gaining approval and extraordinary funding from the relevant bodies, developing a new protocol within the trust and the logistics of carrying out the procedure safely. METHODS: We describe the case of a 61-year-old paraplegic woman with insensate legs who presented with a 5-week old 2% TBSA deep dermal to full-thickness scald burn which was sustained accidentally in the shower. In view of the prolonged healing time and the risk of burn wound infection, skin grafting of the wound was the recommended treatment. However, given the high risk of impaired wound healing in denervated skin of quadriplegic individuals, the patient was warned of potential donor site wound healing problems. This, along with concerns over the donor site area interfering with the use of her mobility aids prompted her homozygotic twin sister to donate the necessary skin. The process was risk assessed and approval was sought from the Trust's Caldicott Guardian, NHS Specialist Commissioners and the Trust's Human Tissue Authority (HTA) Designated Individual (DI). A new protocol for the pathway in line with HTA guidance was developed. Specific patient information documents were written, psychological assessments performed and specific consent for skin donation undertaken. One week prior to and again on the day of the procedure, the donor was serologically screened for communicable diseases. A donor medical and social history assessment was also carried out. RESULTS: There was 100% graft take at day 5 post-surgery. The sister's donor site healed well by day 13. At 3 months, there were no signs of hypertrophic scarring. No additional outpatient or dressing clinic appointment were required. DISCUSSION: This is the first case of successful skin homografting between monozygotic twins in the United Kingdom. Donation of skin grafts between such patients, however, requires clinical justification, twin zygosity DNA testing, approval from the HTA and NHS commissioners with appropriate protocols and procedures in place to ensure patient safety. Liaising with the local Tissue Bank can facilitate this process. CONCLUSION: Skin grafting between identical twins is a feasible and successful procedure and offers an alternative treatment modality when wound healing in the recipient twin is suboptimal or when severely burnt. This principle should also be considered, in appropriate cases, for composite tissue transfer in situations where complex reconstructions are required.

Accuracy of Predicted Resection Weights in Breast Reduction Surgery.

BACKGROUND: Many insurance carriers continue to deny coverage for reduction mammaplasty unless a minimum amount of resected breast tissue per breast is achieved during surgery. This study investigates the accuracy of preoperative prediction that a minimum weight of 500 g can be resected and evaluates potential risk factors for not meeting this insurance requirement. METHODS: A retrospective review was performed on 445 patients with bilateral symptomatic macromastia who sought consultation for breast reduction surgery from 2007 to 2012. Women were included for analysis if they had documented predicted resection weights and underwent small-to-moderate breast reduction (< 1,000 g per side; n = 323). Relevant demographic information, mean predicted resection weight, and the mean actual resection weight were collected for analysis. RESULTS: Surgeon prediction of resection weight being over 500 g had a positive predictive value of 73%. In 61 patients (19%), the predicted weights were ≥ 500 g, but the actual weights were < 500 g. Thirty percentage of these 61 patients did not meet either Schnur or minimum weight requirements. Women with a body mass index < 30 were at significantly increased odds (odds ratio, 3.76; 95% confidence interval, 1.89-7.48; P = 0.002) of not meeting the minimum weight requirement at surgery compared with patients with a body mass index ≥ 30. CONCLUSIONS: The common insurance criterion of removing ≥ 500 g per breast during breast reduction surgery are not met in a distinct cohort of women who are clinically appropriate candidates. This risk is particularly increased in nonobese women possibly due to proportionately smaller breast mass compared with obese women.

A systematic review of morbidity associated with autologous breast reconstruction before and after exposure to radiotherapy: are current practices ideal?

PURPOSE: The specific aim of this study was to conduct a systematic review of the literature to assess outcomes data on complications and aesthetic results associated with autologous tissue-based breast reconstruction performed before or after chest wall irradiation. METHODS: Studies from a PubMed search that met predetermined inclusion criteria were identified. Complications of interest included partial or total flap loss, fat necrosis, thrombosis, infection, seroma, hematoma, delayed wound healing, and flap fibrosis/contracture. Pooled complication rates were calculated. RESULTS: A total of 20 articles were included in the study for autologous reconstruction. These primary articles were selected after screening 897 publications, with six studies presenting data on pre-reconstruction radiation, nine studies presenting data on post-reconstruction radiation, and five studies presenting data on both patient groups. Comparison of pooled complication rates between flaps irradiated before or after reconstruction were statistically similar, including total flap loss (1 vs. 4 %), wound healing complications (10 vs. 14 %), infection (4 vs. 6 %), hematoma (2 vs. 1 %), seroma (4 vs. 4 %), and fat necrosis (10 vs. 13 %). The pooled rate of flap contracture and fibrosis was 27 % in flap reconstructions exposed to radiotherapy. Statistical evaluation of aesthetic outcomes was impossible as a result of variability in assessment and reporting methods. CONCLUSIONS: Review of the current literature suggests similar rates of complications and success rates in autologous breast reconstruction patients exposed to pre- or post-reconstruction radiation. Immediate autologous reconstruction should be considered as a viable option even in patients who are likely to require postmastectomy radiotherapy.

A systematic review of complications of implant-based breast reconstruction with prereconstruction and postreconstruction radiotherapy.

PURPOSE: To conduct a systematic review of the literature to assess outcomes data on complications associated with implant-based breast reconstruction performed before or after chest wall radiation to assist in guiding the decision-making process for reconstruction of the irradiated breast. METHODS: Studies from a PubMed search that met predetermined inclusion criteria were identified and included. Complications of interest were low- and high-grade capsular contractures, minor and major complications, reconstruction failure rates, and reconstruction completion rates. Pooled complication rates were calculated. RESULTS: A total of 26 articles were included in the study after screening 1,006 publications, with 14 studies presenting data on prereconstruction radiation and 23 studies presenting data on postreconstruction radiation. Complication rates evaluated in patients exposed to radiation before or after implant reconstruction were not significantly different. Reconstruction failure rates were similar at 19 and 20 % for pre- and postreconstruction radiation patients, respectively. Completion rates were similar at 83 and 80 % for pre- and postreconstruction radiation patients, respectively. CONCLUSIONS: Review of the current literature suggests similar overall success and failure rates with radiotherapy provided both before and after reconstruction. Failure rates in both groups of patients are clinically significant when considering implant reconstruction in the setting of radiation.