Computational Design and Manufacturing of Sustainable Materials through First-Principles and Materiomics.

Engineered materials are ubiquitous throughout society and are critical to the development of modern technology, yet many current material systems are inexorably tied to widespread deterioration of ecological processes. Next-generation material systems can address goals of environmental sustainability by providing alternatives to fossil fuel-based materials and by reducing destructive extraction processes, energy costs, and accumulation of solid waste. However, development of sustainable materials faces several key challenges including investigation, processing, and architecting of new feedstocks that are often relatively mechanically weak, complex, and difficult to characterize or standardize. In this review paper, we outline a framework for examining sustainability in material systems and discuss how recent developments in modeling, machine learning, and other computational tools can aid the discovery of novel sustainable materials. We consider these through the lens of materiomics, an approach that considers material systems holistically by incorporating perspectives of all relevant scales, beginning with first-principles approaches and extending through the macroscale to consider sustainable material design from the bottom-up. We follow with an examination of how computational methods are currently applied to select examples of sustainable material development, with particular emphasis on bioinspired and biobased materials, and conclude with perspectives on opportunities and open challenges.

Interobserver and Intraobserver Reliability of Classification Systems for Radiographic Complications After Radial Head Arthroplasty.

PURPOSE: Although several classifications are used to assess radiographs following radial head arthroplasty (RHA), including the Popovic classification for radiolucency, the Chanlalit classification for stress shielding (SS), the Brooker classification for heterotopic ossification (HO), and the Broberg-Morrey classification for radiocapitellar arthritis, little is known about the reliability of these classification systems. The purpose of this study was to determine the interobserver and intraobserver reliability of these classifications. METHODS: Six orthopedic surgeons at various levels of training reviewed elbow radiographs of 20 patients who underwent RHA and classified them according to the Popovic, Chanlalit, Brooker, and Broberg-Morrey classifications for radiolucency, SS, HO, and RHA, respectively. Four weeks after initial review, radiographic reviews were repeated. Reliability was measured using the Fleiss kappa and the intraclass correlation coefficient. Agreement was interpreted as none (<0), slight (0.01-0.2), fair (0.21-0.4), moderate (0.41-0.6), substantial (0.61-0.8), and almost perfect (0.81-1) based on agreement among attending surgeons. RESULTS: Among fellowship-trained attending surgeons, interobserver reliability was slight for SS (Chanlalit) and the categorical interpretation of radiolucency (Popovic), fair for radiocapitellar arthritis (Broberg-Morrey) and HO (Brooker), and substantial for the ordinal interpretation of radiolucency (Popovic). Residents had a higher interobserver reliability than attending physicians when using the Brooker classification. Mean intraobserver reliability was fair for SS (Chanlalit) and the categorical interpretation of radiolucency (Popovic), moderate for HO (Brooker) and radiocapitellar arthritis (Broberg-Morrey), and almost perfect for the ordinal interpretation of radiolucency (Popovic). Trainees had higher intraobserver reliability than attending surgeons using the SS (Chanlalit) classification. CONCLUSIONS: The number of Popovic zones is reliable for communication between physicians, but caution should be taken with the Brooker, Chanlalit, Broberg-Morrey, and categorical interpretation of the Popovic classifications. All the classifications had better intraobserver than interobserver reliability. CLINICAL RELEVANCE: Reliability of classification systems for radiographic complications after RHA is less than substantial except the number of zones of radiolucency; therefore, caution is required when drawing conclusions based on these classifications.

Anatomic Radial Head Arthroplasty: The Importance of Implant Angle.

PURPOSE: Multifragmentary radial head and neck fractures not amenable to open reduction and internal fixation are usually treated with radial head arthroplasty (RHA). Although the optimal implant design is still subject to debate, anatomic designs are common. We hypothesized that positioning of the implant leading to increased radial stem angle (RSA) (angle of the RHA stem with respect to the proximal radius shaft, RSA) in anatomic RHA designs will contribute to failures. The aim of this study was to characterize the risk of RHA failure with respect to the stem angle in anatomic RHA design. METHODS: A retrospective review of patients who underwent anatomic RHA for acute fractures between 2006 and 2019 at 2 academic centers was conducted. Initial postoperative elbow radiographs were reviewed to measure RSA on the anterior-posterior and lateral views. Radiolucency, stress shielding, and radiocapitellar arthritis were also evaluated. Implant failure was defined as prosthesis removal or revision. RESULTS: Implant failure was associated with significantly larger lateral RSA than that in intact implants. Increasing stem shaft angle on a lateral radiograph was associated with decreased implant survival. Radiolucency, stress shielding, and radiocapitellar arthritis were similar between the 2 groups. CONCLUSIONS: Anatomic radial head implants are commonly used; however, the importance of prosthesis positioning, specifically that of the stem within the proximal radius, remains understudied. Higher RSA is associated with the risk of implant failure and need for revision. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

The Validity and Reliability of a Pocket-Sized Ultrasound to Diagnose Distal Radius Fracture and Assess Quality of Closed Reduction.

PURPOSE: Handheld ultrasound technology is increasingly used in health care. Its use for fracture care has not been adequately evaluated. The purpose of this study was to evaluate handheld, pocket-sized ultrasound in the diagnosis and assessment of reductions in distal radius fractures. METHODS: A total of 23 patients with distal radius fractures (average age, 53 years; 13 women) and 20 control patients (average age, 53 years; 10 women) were prospectively enrolled. All patients with distal radius fractures underwent standard, 3-view radiographic and ultrasonographic examinations of the wrist before and after closed reduction. Control patients had a one-time standard radiographic and ultrasonographic examination of the wrist. Radiographs were used as the reference standard. All images were assessed for the presence or absence of a fracture by a board-certified, hand fellowship-trained orthopedic surgeon and musculoskeletal fellowship-trained radiologist who were blinded to the study protocol. If a fracture was detected, the adequacy of reduction was assessed. RESULTS: The sensitivity of distal radius fracture diagnosis on ultrasound was 100% and specificity ranged from 90% to 95%. The sensitivity of identifying a satisfactory reduction ranged from 76% to 93% and specificity was 93% to 94%. Interrater reliability between the musculoskeletal radiologist and hand surgeon was κ = 0.86 for diagnosing the fracture and κ = 0.82 for identifying a satisfactory reduction. Intrarater reliability ranged from κ = 0.82 to 0.86. CONCLUSIONS: A pocket-sized, handheld diagnostic ultrasound device demonstrates the ability to diagnose distal radius fractures and assess fracture reductions. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

Rat posterior facial vein interpositional graft: a more relevant training model.

Microvascular training models for vein grafting most often use the rat epigastric vein interpositioned to the femoral artery. We describe the rat posterior facial vein as an alternative vein graft model; it has at least a 2:1 diametric ratio to the femoral artery and a tougher connective tissue, making it more similar to clinical vein grafting for reconstructive microsurgery. A series of 24 grafts interpositioned to the femoral artery were done using 11-12 sutures per end-to-end anastomosis and yielded early patency rates of 96% at 20 min and 92% at 2 and 4 weeks for subsets of 12 grafts. As a training model the diametric disparity provides unique challenges with clinical relevance, for which a number of different techniques for matching arterial to venous circumferences can be done.

Robust myco-composites: a biocomposite platform for versatile hybrid-living materials.

Fungal mycelium, a living network of filamentous threads, thrives on lignocellulosic waste and exhibits rapid growth, hydrophobicity, and intrinsic regeneration, offering a potential means to create next-generation sustainable and functional composites. However, existing hybrid-living mycelium composites (myco-composites) are tremendously constrained by conventional mold-based manufacturing processes, which are only compatible with simple geometries and coarse biomass substrates that enable gas exchange. Here we introduce a class of structural myco-composites manufactured with a novel platform that harnesses high-resolution biocomposite additive manufacturing and robust mycelium colonization with indirect inoculation. We leverage principles of hierarchical composite design and selective nutritional provision to create a robust myco-composite that is scalable, tunable, and compatible with complex geometries. To illustrate the versatility of this platform, we characterize the impact of mycelium colonization on mechanical and surface properties of the composite. We found that our method yields the strongest mycelium composite reported to date with a modulus of 160 MPa and tensile strength of 0.72 MPa, which represents over a 15-fold improvement over typical mycelium composites, and further demonstrate unique applications with fabrication of foldable bio-welded containers and flexible mycelium textiles. This study bridges the gap between biocomposite and hybrid-living materials research, opening the door to advanced structural mycelium applications and demonstrating a novel platform for development of diverse hybrid-living materials.

Return to Play After Thumb Ulnar Collateral Ligament Injuries Managed Surgically in Athletes-A Systematic Review.

Purpose: The purpose of this systematic review was to summarize the available data on how surgical management of injuries to the thumb ulnar collateral ligament (UCL) complex affects athletes and their return-to-play (RTP) and postinjury performance metrics in addition to evaluating rehabilitation guidelines. Methods: A systematic search was performed on PubMed and Embase databases for articles on outcomes of surgical treatment of thumb UCL injuries in athletes. Articles with expert recommendations on postoperative management and RTP guidelines were also included separately. Study characteristics were recorded, including sport, RTP rates, and data on performance. Recommendations were summarized by sport. The Methodological Index for Non-Randomized Studies (MINORS) criteria was used to assess methodological quality. The authors also present their recommended return-to-sport algorithm. Results: Twenty-three articles were included, including 11 with reports on patients and 12 expert opinions on guiding RTP. The mean MINORS score for the applicable studies was 9.4. In the 311 patients included, RTP was 98.1% in aggregate. No performance detriments were noted in athletes after surgery. Thirty-two (10.3%) patients had postoperative complications. The recommendations on timing to RTP vary by sport and author, but all recommended initial thumb protection when returning to sport. Newer techniques, such as suture tape augmentation, suggest the permission for earlier motion. Conclusions: Return-to-play rates after surgical treatment of thumb UCL injuries are high, with reassuring return to preinjury level of play with few complications. Recommendations for surgical technique have trended toward suture anchors and, now, suture tape augmentation with earlier motion protocols, although rehabilitation guidelines vary by sport and author. Current information on thumb UCL surgery in athletes is limited by the low quality of evidence and expert recommendations. Type of study/level of evidence: Prognostic IV.

An automated biomateriomics platform for sustainable programmable materials discovery.

Recently, the potential to create functional materials from various forms of organic matter has received increased interest due to its potential to address environmental concerns. However, the process of creating novel materials from biomass requires extensive experimentation. A promising means of predicting the properties of such materials would be the use of machine-learning models trained on or integrated into self-learned experimental data and methods. We outline an automated system for the discovery and characterization of novel, sustainable, and functional materials from input biomass. Artificial intelligence provides the capacity to examine experimental data, draw connections between composite composition and behavior, and design future experiments to expand the system's understanding of the studied materials. Extensions to the system are described that could further accelerate the discovery of sustainable composites, including the use of interpretable machine-learning methods to expand the insights gleaned from to human-readable materiomic insights about material process-structure-functional relationships.

Management of soft-tissue coverage of open tibia fractures in Latin America: Techniques, timing, and resources.

PURPOSE: This study examined soft-tissue coverage techniques of open tibia fractures, described soft-tissue treatment patterns across income groups, and determined resource accessibility and availability in Latin America. METHODS: A 36-question survey was distributed to orthopaedic surgeons in Latin America through two networks: national orthopaedic societies and the Asociación de Cirujanos Traumatólogos de las Américas (ACTUAR). Demographic information was collected, and responses were stratified by income groups: high-income countries (HICs) and middle-income countries (MICs). RESULTS: The survey was completed by 469 orthopaedic surgeons, representing 19 countries in Latin America (2 HICs and 17 MICs). Most respondents were male (89%), completed residency training (96%), and were fellowship-trained (71%). Only 44% of the respondents had received soft-tissue training. Respondents (77%) reported a strong interest in attending a soft-tissue training course. Plastic surgeons were more commonly the primary providers for Gustilo Anderson (GA) Type IIIB injuries in HICs than in MICs (100% vs. 47%, p<0.01) and plastic surgeons were more available (<24 h of patient presentation to the hospital) in HICs than MICs (63% vs. 26%, p = 0.05), demonstrating statistically significant differences. In addition, respondents in HICs performed free flaps more commonly than in MICs for proximal third (55% vs. 10%, p<0.01), middle third (36% vs. 9%, p = 0.02), and distal third (55% vs. 10%, p<0.01) lower extremity wounds. Negative Pressure Wound Therapy (NPWT or Wound VAC) was the only resource available to more than half of the respondents. Though not statistically significant, surgeons reported having more access to plastic surgeons at their institutions in HICs than MICs (91% vs. 62%, p = 0.12) and performed microsurgical flaps more commonly at their respective institutions (73% vs. 42%, p = 0.06). CONCLUSIONS: The study demonstrated that most orthopaedic surgeons in Latin America have received no soft-tissue training, HICs and MICs have differences in access to plastic surgeons and expectations for flap type and timing to definitive coverage, and most respondents had limited access to necessary soft-tissue surgical resources. Further investigation into differences in the clinical outcomes related to soft-tissue coverage methods and protocols can provide additional insight into the importance of timing and access to specialists.

Retinal Organoids Long-Term Functional Characterization Using Two-Photon Fluorescence Lifetime and Hyperspectral Microscopy.

Pluripotent stem cell-derived organoid technologies have opened avenues to preclinical basic science research, drug discovery, and transplantation therapy in organ systems. Stem cell-derived organoids follow a time course similar to species-specific organ gestation in vivo. However, heterogeneous tissue yields, and subjective tissue selection reduce the repeatability of organoid-based scientific experiments and clinical studies. To improve the quality control of organoids, we introduced a live imaging technique based on two-photon microscopy to non-invasively monitor and characterize retinal organoids' (RtOgs') long-term development. Fluorescence lifetime imaging microscopy (FLIM) was used to monitor the metabolic trajectory, and hyperspectral imaging was applied to characterize structural and molecular changes. We further validated the live imaging experimental results with endpoint biological tests, including quantitative polymerase chain reaction (qPCR), single-cell RNA sequencing, and immunohistochemistry. With FLIM results, we analyzed the free/bound nicotinamide adenine dinucleotide (f/b NADH) ratio of the imaged regions and found that there was a metabolic shift from glycolysis to oxidative phosphorylation. This shift occurred between the second and third months of differentiation. The total metabolic activity shifted slightly back toward glycolysis between the third and fourth months and stayed relatively stable between the fourth and sixth months. Consistency in organoid development among cell lines and production lots was examined. Molecular analysis showed that retinal progenitor genes were expressed in all groups between days 51 and 159. Photoreceptor gene expression emerged around the second month of differentiation, which corresponded to the shift in the f/b NADH ratio. RtOgs between 3 and 6 months of differentiation exhibited photoreceptor gene expression levels that were between the native human fetal and adult retina gene expression levels. The occurrence of cone opsin expression (OPN1 SW and OPN1 LW) indicated the maturation of photoreceptors in the fourth month of differentiation, which was consistent with the stabilized level of f/b NADH ratio starting from 4 months. Endpoint single-cell RNA and immunohistology data showed that the cellular compositions and lamination of RtOgs at different developmental stages followed those in vivo.

Management of Metadiaphyseal Proximal Radius Fractures.

Metadiaphyseal proximal radius fractures blur the distinction between the radial neck and radial shaft fractures. Operative management presents unique technical challenges both in terms of surgical approach and fixation method. We discuss relevant anatomy, safe surgical approach, and options and techniques for fracture fixation. We describe 6 patients who achieved satisfactory functional outcomes, even in cases of severe bone loss secondary to ballistic trauma. An extensile dorsal approach with exposure of the posterior interosseous nerve is recommended when normal soft tissue intervals have not already been extensively disrupted. Robust fixation can be achieved by contouring and repurposing a variety of plates such as a variety of mini fragment plates (2.4 mm T or Y-plates), flexible nails, or even distal radius plates.

A Biomechanical Comparison of Fiberglass Casts and 3-Dimensional-Printed, Open-Latticed, Ventilated Casts.

Background: The aim of this study was to quantify the stabilizing properties of a 3-dimensional (3D)-printed short-arm cast and compare those properties with traditional fiberglass casts in a cadaveric subacute distal radius fracture model. Methods: A cadaveric subacute fracture model was created in 8 pairs of forearms. The specimens were equally allocated to a fiberglass cast or 3D-printed cast group. All specimens were subjected to 3 biomechanical testing modalities simulating daily life use: flexion and extension of digits, pronation and supination of the hand, and 3-point bending. Between each loading modality, radiological evaluation of the specimens was performed to evaluate possible interval displacement. Interfragmentary motion was quantified using a 3D motion-tracking system. Results: Radiographic assessment did not reveal statistically significant differences in radiographic parameters between the 2 groups before and after biomechanical testing. A statistically significant difference in interfragmentary motion was calculated with the 3-point bending test, with a mean difference of 0.44 (±0.48) mm of motion. Conclusions: A statistically significant difference in interfragmentary motion between the 2 casting groups was only identified in 3-point bending. However, the clinical relevance of this motion remains unclear as the absolute motion is less than 1 mm. The results of this study show noninferiority of the 3D-printed casts compared with the traditional fiberglass casts in immobilizing a subacute distal radius fracture model. These results support the execution of a prospective randomized clinical trial comparing both casting techniques.

Orthopaedic Residents' Interpretation of Point-of-Care Assessment of Distal Radial Fractures with Use of Pocket-Sized Ultrasound Devices.

BACKGROUND: Musculoskeletal ultrasonography is a tool that is being used increasingly. However, the interpretation of ultrasound images of fractures is not incorporated into orthopaedic training programs. This paper presents the results of an initiative to train orthopaedic surgery residents to accurately interpret images of distal radial fractures in adults and to assess their confidence levels and attitudes regarding their future use of ultrasonography. METHODS: Six junior residents were given a pretest with 100 distal radial images that had been made with a pocket-sized ultrasound device; they were asked to determine fracture versus nonfracture cases (50 cases) as well as reduced fracture versus nonreduced fracture cases (50 cases). Following the pretest, residents completed a 30-minute tutorial (didactic and practical) on distal radial ultrasonography. The residents then completed a period of self-practice during 2 separate trauma rotations (a total of 14 to 16 weeks in a single academic year). Following completion of their second trauma rotation, the residents completed a posttest. Comfort level using a pocket-sized ultrasound device also was assessed during pretesting and posttesting. RESULTS: The median number of days from the pretest to the posttest was 212 days (range, 175 to 225 days). Residents demonstrated an overall improvement in positive predictive value (PPV) of identifying a fracture from the pretest (86.0%; range, 77.5% to 93.1%) to the posttest (93.5%; range, 91.4% to 94.2%). The overall negative predictive value (NPV) for identifying a fracture also improved from the pretest (69.4%; range, 60.0% to 76.9%) to the posttest (81.0%; range, 76.4% to 86.7%; p = 0.04). The overall PPV for detecting a reduced fracture improved from 67.1% with the pretest (range, 54.2% to 82.4%) to 88.9% with the posttest (range, 83.3% to 94.1%; p = 0.04). The comfort level with using the ultrasound device also increased between pretesting and posttesting, and the residents felt that ultrasonography would be useful in the care of distal radial fractures. CONCLUSIONS: After a focused training session and a period of self-practice, orthopaedic residents improved their interpretation of ultrasound images and their comfort level using pocket-sized ultrasound devices with adult patients with distal radial fractures. Residents felt that a pocket-sized ultrasound device was useful for fracture diagnosis and evaluation of reduction.

Biomechanical Assessment of the Dorsal Spanning Bridge Plate in Distal Radius Fracture Fixation: Implications for Immediate Weight-Bearing.

BACKGROUND: The goal of this study was to compare the biomechanical stability of a 2.4-mm dorsal spanning bridge plate with a volar locking plate (VLP) in a distal radius fracture model, during simulated crutch weight-bearing. METHODS: Five paired cadaveric forearms were tested. A 1-cm dorsal wedge osteotomy was created to simulate an unstable distal radius fracture with dorsal comminution. Fractures were fixed with a VLP or a dorsal bridge plate (DBP). Specimens were mounted to a crutch handle, and optical motion-tracking sensors were attached to the proximal and distal segments. Specimens were loaded in compression at 1 mm/s on a servohydraulic test frame until failure, defined as 2 mm of gap site displacement. RESULTS: The VLP construct was significantly more stable to axial load in a crutch weight-bearing model compared with the DBP plate (VLP: 493 N vs DBP: 332 N). Stiffness was higher in the VLP constructs, but this was not statistically significant (VLP: 51.4 N/mm vs DBP: 32.4 N/mm). With the crutch weight-bearing model, DBP failed consistently with wrist flexion and plate bending, whereas VLP failed with axial compression at the fracture site and dorsal collapse. CONCLUSIONS: Dorsal spanning bridge plating is effective as an internal spanning fixator in treating highly comminuted intra-articular distal radius fracture and prevents axial collapse at the radiocarpal joint. However, bridge plating may not offer advantages in early weight-bearing or transfer in polytrauma patients, with less axial stability in our crutch weight-bearing model compared with volar plating. A stiffer 3.5-mm DBP or use of a DBP construct without the central holes may be considered for distal radius fractures if the goal is early crutch weight-bearing through the injured extremity.

Cobertura de tejidos blandos en una lesión por aplastamiento de la mano en paciente con anemia de células falciformes

Se presenta el caso de una lesión por aplastamiento de la mano derecha en un paciente con historia clínica de anemia de células falciformes. Se realizó la reconstrucción con un colgajo de ingle, seguido de un colgajo de arteria interósea posterior y un colgajo anterolateral de muslo. El tratamiento de estas lesiones es complejo debido a la necesidad de tejidos blandos especializados, difíciles de reproducir para grandes defectos de la palma de la mano; además el grado de desarrollo de tejido cicatricial conduce a contracturas y dificultades en el uso funcional de la mano y los dedos. Este caso se agravó por el historial de anemia de células falciformes del paciente.

We report the case of a crush injury to the right hand in a patient with a clinical history of sickle cell anemia. Reconstruction was performed with a groin flap, followed by a posterior interosseous artery flap and an anterolateral thigh flap. The treatment of these injuries was complex due to the need for specialized soft tissues, which are difficult to reproduce for large defects in the palm of the hand. In addition, the degree of development of scar tissue leads to contractures and difficulties in the functional use of the hand and fingers. This case was aggravated by the patient's history of sickle cell anemia.

Anatomic Knowledge and Perceptions of the Adequacy of Anatomic Education Among Applicants to Orthopaedic Residency.

BACKGROUND: The time dedicated to the study of human anatomy within medical school curriculums has been substantially reduced. The effect of this on the knowledge of incoming orthopaedic trainees is unknown. The current study aimed to evaluate both the subjective perceptions and objective anatomic knowledge of fourth-year medical students applying for orthopaedic residency. METHODS: A multicenter prospective study was performed that assessed 224 students during the course of their interview day for an orthopaedic residency. Participants provided demographic data and a subjective assessment of the quality of their anatomic education, and completed either an upper or lower extremity anatomic examination. Mean total scores and subscores for various anatomic regions and concepts were calculated. RESULTS: Students on average rated the adequacy of their anatomic education as 6.5 on a 10-point scale. Similarly, they rated the level of importance their medical school placed on anatomic education as 6.2 on a 10-point scale. Almost 90% rated the time dedicated to anatomy as good or fair. Of six possible methods for learning anatomy, dissection was rated the highest.On objective examinations, the mean score for correct answers was 44.2%. This improved to 56.4% when correct and acceptable answers were considered. Regardless of anatomic regions or concepts evaluated, percent correct scores did not reach 50%. There were no significant correlations between performance on the anatomic examinations and either prior academic performance measures or the student's subjective assessment of their anatomic education. CONCLUSIONS: Current students applying into orthopaedic residency do not appear to be adequately prepared with the prerequisite anatomic knowledge. These deficits must be explicitly addressed during residency training to produce competent, safe orthopaedic surgeons.

Bioavailability and antioxidant effect of epigallocatechin gallate administered in purified form versus as green tea extract in healthy individuals.

Tea polyphenols have strong in vitro antioxidant activity. Due to their limited bioavailability, however, their contribution to in vivo antioxidant activity may depend on the form of administration. A human intervention study was performed to evaluate the bioavailability and antioxidant capacity of (-)-epigallocatechin-3-gallate (EGCG) administered as a single large dose in the form of either purified EGCG or as green tea extract (Polyphenon E). Plasma concentrations of tea polyphenols were determined by high-performance liquid chromatography (HPLC) analysis combined with coulometric array electrochemical detection (ECD). We found no differences in plasma EGCG concentrations and trolox equivalents determined by the trolox equivalent antioxidant capacity assay after administration of either form of EGCG. However, we found that the plasma antioxidant activity was significantly affected by changes in the plasma urate concentration, which may have interfered with the effect of tea polyphenols on the antioxidant activity. In addition, lymphocyte 8-hydroxydeoxyguanosine to deoxyguanosine (8-OHdG/10(6)dG) ratios were determined by HPLC with ECD. The 8-OHdG/10(6)dG ratios did not change significantly during the 24 h following both EGCG interventions but correlated significantly within individuals determined during the two interventions separated by 1 week. In summary, changes in plasma uric acid due to dietary intake were significantly correlated to the plasma antioxidant activity and exerted a stronger influence on the plasma antioxidant activity compared with the EGCG intervention. In future studies of dietary effects on the plasma antioxidant capacity, changes in plasma uric acid will need to be closely monitored.

Bioavailability and antioxidant activity of tea flavanols after consumption of green tea, black tea, or a green tea extract supplement.

BACKGROUND: Green and black tea polyphenols have been extensively studied as cancer chemopreventive agents. Many in vitro experiments have supported their strong antioxidant activity. Additional in vivo studies are needed to examine the pharmacokinetic relation of absorption and antioxidant activity of tea polyphenols administered in the form of green or black tea or tea extract supplements. OBJECTIVE: The purpose of this study was to compare the pharmacokinetic disposition of tea polyphenols and their effect on the antioxidant capacity in plasma 8 h after a bolus consumption of either green tea, black tea, or a green tea extract supplement. DESIGN: Thirty healthy subjects were randomly assigned to 3 different sequences of green tea, black tea, or a green tea extract supplement in a 3 x 3 crossover design with a 1-wk washout period in between treatments. RESULTS: Flavanol absorption was enhanced when tea polyphenols were administered as a green tea supplement in capsule form and led to a small but significant increase in plasma antioxidant activity compared with when tea polyphenols were consumed as black tea or green tea. All 3 interventions provided similar amounts of (-)-epigallocatechin-3-gallate. CONCLUSIONS: Our observations suggest that green tea extract supplements retain the beneficial effects of green and black tea and may be used in future chemoprevention studies to provide a large dose of tea polyphenols without the side effects of caffeine associated with green and black tea beverages.

Tea polyphenols and theaflavins are present in prostate tissue of humans and mice after green and black tea consumption.

Green and black tea have shown promise in the chemoprevention of prostate cancer. The objective of this study was to determine the bioavailability and bioactivity of tea polyphenols (PP) and theaflavins in human serum and human and mouse tissues. A decaffeinated black tea diet was administered to C57BL/6 mice. PPs and theaflavins were found in the small and large intestine, liver, and prostate in conjugated and free forms. The relative prostate bioavailability of theaflavin was 70% higher than that of epigallocatechin gallate (EGCG). In the second mouse study, a green tea (GT) diet was administered followed by the control diet for 1-5 d. Epicatechin (EC), EGCG, and epicatechin gallate (ECG) concentrations in prostate tissue were significantly decreased after 1 d of consuming the control diet. Epigallocatechin gallate (EGC), however, did not decrease significantly. For the human study, 20 men scheduled for surgical prostatectomy were randomly assigned to consume 1.42 L daily of GT, BT, or a caffeine-matched soda control (SC) for 5 d before radical prostatectomy. Tea PPs were greater in prostate samples from men consuming BT and GT than in men consuming SC (P = 0.0025). Although tea PP were not detectable in serum, ex vivo LNCaP prostate cancer cell proliferation was less when cells were grown in media containing patient serum collected after BT (P < 0.001) and GT (P = 0.025) consumption relative to baseline serum This is the first human study to show that tea polyphenols and theaflavins are bioavailable in the prostate where they may be active in the prevention of prostate cancer.