Achieving the Optimal Aesthetic Benefit While Correcting Midface Deficiency: Utilizing A High Winged Le Fort I in Cleft and Craniofacial Patients.

ABSTRACT: Craniofacial anomalies are congenital disorders that affect the cranium and facial bones, with cleft lip and palate being the most common. These anomalies are often associated with abnormal development of pharyngeal arches and can result in the development of class III malocclusion and severe maxillary retrusion. Current treatment includes orthodontic decompensation and Le Fort I osteotomy to correct the maxillomandibular relationship. However, the traditional Le Fort I (LFI) advancement does not fully address the lack of skeletal volume in the midface. The high winged Le Fort I osteotomy (HWLFI) is an excellent surgical option for simultaneous correction of the midface deficiency and malocclusion while restoring optimal esthetic convexity. A retrospective chart review was conducted to include all cleft and craniofacial patients who underwent HWLFI advancement from 2002 to 2018. Patients had a minimum of 12 months of follow-up. Patient data and complications were reviewed. Standardized facial photographs were analyzed for esthetic improvement, occlusion, and beneficial salutary effects on the midface. Forty-three patients met the inclusion criteria. The mean age at surgery was 18.9 years. The mean follow-up was 32 months. Early complications included infection (9.3%) and temporary nerve paresthesia (2.3%). Late complications included infection (6.5%), wound dehiscence (4.3%), and painful hardware (2.3%). One patient (2.3 percent) had clinically significant relapse that required surgery. Postoperatively, patients demonstrated excellent midface projection and correction of the skeletal malocclusion. The HWLFI advancement significantly improves both the malocclusion and esthetic concerns of cleft and craniofacial patients by reestablishing maximal midfacial support. Important advantages of the HWLFI are avoidance of alloplastic implant use and extensive and potentially unstable surgical procedures that increase orbital volume.

Probability of Opioid Prescription Refilling After Surgery: Does Initial Prescription Dose Matter?

OBJECTIVE: We sought to determine the correlation between the probability of postoperative opioid prescription refills and the amount of opioid prescribed, hypothesizing that a greater initial prescription yields a lower probability of refill. BACKGROUND: Although current guidelines regarding opioid prescribing largely address chronic opioid use, little is known regarding best practices and postoperative care. METHODS: We analyzed Optum Insight claims data from 2013 to 2014 for opioid-naïve patients aged 18 to 64 years who underwent major or minor surgical procedures (N = 26,520). Our primary outcome was the occurrence of an opioid refill within 30 postoperative days. Our primary explanatory variable was the total oral morphine equivalents provided in the initial postoperative prescription. We used logistic regression to examine the probability of an additional refill by initial prescription strength, adjusting for patient factors. RESULTS: We observed that 8.67% of opioid-naïve patients refilled their prescriptions. Across procedures, the probability of a single postoperative refill did not change with an increase with initial oral morphine equivalents prescribed. Instead, patient factors were correlated with the probability of refill, including tobacco use [odds ratio (OR) 1.42, 95% confidence interval (CI) 1.23-1.57], anxiety (OR 1.30, 95% CI 1.15-1.47), mood disorders (OR 1.28. 95% CI 1.13-1.44), alcohol or substance abuse disorders (OR 1.43, 95% CI 1.12-1.84), and arthritis (OR 1.21, 95% CI 1.10-1.34). CONCLUSIONS: The probability of refilling prescription opioids after surgery was not correlated with initial prescription strength, suggesting surgeons could prescribe smaller prescriptions without influencing refill requests. Future research that examines the interplay between pain, substance abuse, and mental health could inform strategies to tailor opioid prescribing for patients.

"Blunt adrenal injury does not affect outcomes in adult patients with isolated abdominal injury - A National Trauma Data Bank review®".

INTRODUCTION: Traumatic blunt adrenal injury (BAI) has been an area of debate, with conflicting data on its impact. BAI from blunt abdominal injury is challenging to diagnose early due to retroperitoneal gland location and minimal clinical signs. The incidence of BAI ranges from 0.03 % to 4.95 %, with an increasing trend attributed to advanced CT imaging. Conflicting data exists regarding BAI's implications on patient outcomes, necessitating a comprehensive evaluation. METHODS: A retrospective review of the National Trauma Data Bank (NTDB®) for 2017-2021 included a total of 352,654 patients with 337,628 polytrauma patients and 15,026 isolated abdominal trauma patients. Patients were categorized into those with and without adrenal injury. Demographic data and outcomes were compared using statistical tests, focusing on Injury Severity Scores (ISS), mortality, length of stay, and ventilation days. RESULTS: Polytrauma patients with BAI had increased mortality, longer ICU and hospital stays, and ventilation requirements when compared to polytrauma patients without BAI. However, when evaluating isolated abdominal trauma patients with BAI showed no significant differences when compared to isolated abdominal trauma without BAI in mortality or ICU LOS and a slight decrease in ICU admissions, hospital LOS, and ventilation requirement. DISCUSSION: The study indicates a significant association between BAI and increased trauma severity among polytrauma patients. Mortality, however, did not exhibit a consistent rise across all patients with adrenal injury, emphasizing that BAI may not independently influence outcomes. These findings align with the notion that adrenal injury is linked to the overall trauma burden rather than being a primary determinant of mortality.

"Blunt adrenal injury does not affect outcomes in the pediatric population with isolated abdominal injury- a National Trauma Data Bank Review®."

BACKGROUND: The incidence of blunt abdominal injury (BAI) in the adult population has been estimated to be between 0.03% and 4.95%. However, the impact of BAI on the pediatric population remains unknown. METHODS: We conducted a retrospective review of National Trauma Data Bank datasets for the years 2017-2019. We included patients under the age of 18 who experienced blunt trauma and had suffered a blunt abdominal injury with an Abbreviated Injury Scale (AIS) severity score of 2 or higher. RESULTS: Out of the 8064 pediatric patients with isolated abdominal trauma, 134 patients also suffered from BAI. We found no difference in the outcomes of patients with blunt adrenal injury in terms of mortality, length of stay in the intensive care unit (ICU) and hospital, and the number of ventilator days. Within poly-trauma patients BAI was associated with worst patient outcomes. CONCLUSIONS: This study demonstrates that BAI has minimal clinical impact on patient outcomes in isolation. However it is associated with worst outcomes in poly trauma patients suggesting correlation with increased trauma burden. LEVEL OF EVIDENCE: III.

Benefits of Early Utilization of Palliative Care Consultation in Trauma Patients.

OBJECTIVES: To determine the effects of palliative care consultation if performed within 72 hours of admission on length of stay (LOS), mortality, and invasive procedures. DESIGN: Retrospective observational study. SETTING: Single-center level 1 trauma center. PATIENTS: Trauma patients, admitted to ICU with palliative care consultation. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: The ICU LOS was decreased in the early palliative care (EPC) group compared with the late palliative care (LPC) group, by 6 days versus 12 days, respectively. Similarly, the hospital LOS was also shorter in the EPC group by 8 days versus 17 days in the LPC group. In addition, the EPC group had lower rates of tracheostomy (4% vs 14%) and percutaneous gastrostomy tubes (4% vs 15%) compared with the LPC group. There was no difference in mortality or discharge disposition between patients in the EPC versus LPC groups. It is noteworthy that the patients who received EPC were slightly older, but there were no other significant differences in demographics. CONCLUSIONS: EPC is associated with fewer procedures and a shorter amount of time spent in the hospital, with no immediate effect on mortality. These outcomes are consistent with studies that show patients' preferences toward the end of life, which typically involve less time in the hospital and fewer invasive procedures.

Dataset of 143 metagenome-assembled genomes from the Arctic and Atlantic Oceans, including 21 for eukaryotic organisms.

This article presents metagenome-assembled genomes (MAGs) for both eukaryotic and prokaryotic organisms originating from the Arctic and Atlantic oceans, along with gene prediction and functional annotation for MAGs from both domains. Eleven samples from the chlorophyll-a maximum layer of the surface ocean were collected during two cruises in 2012; six from the Arctic in June-July on ARK-XXVII/1 (PS80), and five from the Atlantic in November on ANT-XXIX/1 (PS81). Sequencing and assembly was carried out by the Joint Genome Institute (JGI), who provide annotation of the assembled sequences, and 122 MAGs for prokaryotic organisms. A subsequent binning process identified 21 MAGs for eukaryotic organisms, mostly identified as Mamiellophyceae or Bacillariophyceae. The data for each MAG includes sequences in FASTA format, and tables of functional annotation of genes. For eukaryotic MAGs, transcript and protein sequences for predicted genes are available. A spreadsheet is provided summarising quality measures and taxonomic classifications for each MAG. These data provide draft genomes for uncultured marine microbes, including some of the first MAGs for polar eukaryotes, and can provide reference genetic data for these environments, or used in genomics-based comparison between environments.

Metagenome-assembled genomes of phytoplankton microbiomes from the Arctic and Atlantic Oceans.

BACKGROUND: Phytoplankton communities significantly contribute to global biogeochemical cycles of elements and underpin marine food webs. Although their uncultured genomic diversity has been estimated by planetary-scale metagenome sequencing and subsequent reconstruction of metagenome-assembled genomes (MAGs), this approach has yet to be applied for complex phytoplankton microbiomes from polar and non-polar oceans consisting of microbial eukaryotes and their associated prokaryotes. RESULTS: Here, we have assembled MAGs from chlorophyll a maximum layers in the surface of the Arctic and Atlantic Oceans enriched for species associations (microbiomes) with a focus on pico- and nanophytoplankton and their associated heterotrophic prokaryotes. From 679 Gbp and estimated 50 million genes in total, we recovered 143 MAGs of medium to high quality. Although there was a strict demarcation between Arctic and Atlantic MAGs, adjacent sampling stations in each ocean had 51-88% MAGs in common with most species associations between Prasinophytes and Proteobacteria. Phylogenetic placement revealed eukaryotic MAGs to be more diverse in the Arctic whereas prokaryotic MAGs were more diverse in the Atlantic Ocean. Approximately 70% of protein families were shared between Arctic and Atlantic MAGs for both prokaryotes and eukaryotes. However, eukaryotic MAGs had more protein families unique to the Arctic whereas prokaryotic MAGs had more families unique to the Atlantic. CONCLUSION: Our study provides a genomic context to complex phytoplankton microbiomes to reveal that their community structure was likely driven by significant differences in environmental conditions between the polar Arctic and warm surface waters of the tropical and subtropical Atlantic Ocean. Video Abstract.

Management of Calcified Cephalohematoma of Infancy: The University of Michigan 25-Year Experience.

BACKGROUND: Cephalohematoma of infancy is the result of a subperiosteal blood collection that usually forms during birth-related trauma. A small proportion of cephalohematomas can calcify over time, causing a permanent calvarial deformity that is only correctable with surgery. The authors present a technique for the excision and reconstruction of calcified cephalohematoma and their management experience over the past 25 years. METHODS: All patients with a diagnosis of calcified cephalohematoma between 1994 and 2019 were identified. Patients were included if the diagnosis was confirmed by a pediatric plastic surgeon or a neurosurgeon. All patients underwent surgical evaluation followed by surgical intervention or observation. Patient demographics and potential risk factors for both surgical and nonsurgical groups were compared using chi-square or Fisher's exact test. Additional data were collected for the surgical cohort. RESULTS: Of 160 infants diagnosed with cephalohematoma, 72 met inclusion criteria. Thirty patients underwent surgical treatment. There was no significant difference in demographics, baseline characteristics, or potential risk factors between the operative and nonoperative groups. Mean age at the time of surgery was 8.6 months. Twenty-one surgical patients (70 percent) required inlay bone grafting. All surgery patients had improvement in calvarial shape. The main risk of surgery was blood loss requiring transfusion [eight patients (26.7 percent)]. Thirteen percent of patients experienced minor complications. CONCLUSIONS: This series of 72 children with calcified cephalohematomas, 30 of whom required surgical intervention, is one of the largest to date. The technique presented herein demonstrated excellent surgical outcomes by restoring normal cranial contours and was associated with a low complication profile. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Chronic wound healing: A specific antibiofilm protein-asymmetric release system.

Chronic infection is a major cause of delayed wound-healing. It is recognized to be associated with infectious bacterial communities called biofilms. Currently used conventional antibiotics alone often reveal themselves ineffective, since they do not specifically target the wound biofilm. Here, we report a new conceptual tool aimed at overcoming this drawback: an antibiofilm drug delivery system targeting the bacterial biofilm as a whole, by inhibiting its formation and/or disrupting it once it is formed. The system consists of a micro/nanostructured poly(butylene-succinate-co-adipate) (PBSA)-based asymmetric membrane (AM) with controlled porosity. By the incorporation of hydrophilic porogen agents, polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG), we were able to obtain AMs with high levels of porosity, exhibiting interconnections between pores. The PBSA-PEG membrane presented a dense upper layer with pores small enough to block bacteria penetration. Upon using such porogen agents, under dry and wet conditions, membrane's integrity and mechanical properties were maintained. Using bovine serum albumin (BSA) as a model protein, we demonstrated that protein loading and release from PBSA membranes were affected by the membrane structure (porosity) and the presence of residual porogen. Furthermore, the release curve profile consisted of a fast initial slope followed by a second slow phase approaching a plateau within 24 h. This can be highly beneficial for the promotion of wound healing. Cross-sectional confocal laser scanning microscopy (CLSM) images revealed a heterogeneous distribution of fluorescein isothiocyanate (FITC) labeled BSA throughout the entire membrane. PBSA membranes were loaded with dispersin B (DB), a specific antibiofilm matrix enzyme. Studies using a Staphylococcus epidermidis model, indicate significant efficiency in both inhibiting or dispersing preformed biofilm (up to 80 % eradication). The asymmetric PBSA membrane prepared with the PVP porogen (PBSA-PVP) displayed highest antibiofilm activity. Moreover, in vitro cytotoxicity assays using HaCaT and reconstructed human epidermis (RHE) models revealed that unloaded and DB-loaded PBSA-PVP membranes had excellent biocompatibility suitable for wound dressing applications.

Breast Cancer Knowledge and Decisions Made for Contralateral Prophylactic Mastectomy: A Survey of Surgeons and Women in the General Population.

BACKGROUND: Decisions made to undergo contralateral prophylactic mastectomy, in women at low risk for bilateral disease, are often attributed to a lack of knowledge. This study examines the role knowledge plays in determining surgical treatment for unilateral breast cancer made by laywomen and surgeons for themselves or loved ones. METHODS: The study cohort had three groups: (1) laywomen in the general population, (2) breast surgeons, and (3) plastic surgeons. Laywomen were recruited using Amazon Mechanical Turk Crowd Sourcing. Breast and plastic surgeons from nine states were sent electronic surveys. Demographic and contralateral prophylactic mastectomy-specific data on decisions and knowledge were collected and analyzed. RESULTS: Surveys from 1333 laywomen, 198 plastic surgeons, and 142 breast surgeons were analyzed. A significantly greater proportion of laywomen in the general population favored contralateral prophylactic mastectomy (67 percent) relative to plastic (50 percent) and breast surgeons (26 percent) (p < 0.0001). Breast surgeons who chose contralateral prophylactic mastectomy were younger (p = 0.044) and female (0.012). On assessment of knowledge, 78 percent of laywomen had a low level of breast cancer knowledge. Laywomen with higher levels of breast cancer knowledge had lower odds of choosing contralateral prophylactic mastectomy (OR, 0.37; 95 percent CI, 0.28 to 0.49). CONCLUSIONS: Fewer women are likely to make decisions in favor of contralateral prophylactic mastectomy with better breast cancer-specific education. A knowledge gap likely explains the lower rates with which surgeons choose contralateral prophylactic mastectomy for themselves or loved ones; however, some surgeons who were predominantly young and female favor contralateral prophylactic mastectomy. Improving patient education on surgical options for breast cancer treatment is critical, with well-informed decisions as the goal.

The Cost of Contralateral Prophylactic Mastectomy in Women with Unilateral Breast Cancer.

BACKGROUND: Contralateral prophylactic mastectomy may be unnecessary from an oncologic perspective; therefore, the debate persists about the value of contralateral prophylactic mastectomy in women with early-stage unilateral breast cancer. Given finite health care resources, this study aims to evaluate the cost of contralateral prophylactic mastectomy and breast reconstruction. METHODS: Women with unilateral breast cancer undergoing either unilateral mastectomy or unilateral mastectomy with contralateral prophylactic mastectomy and immediate breast reconstruction were selected from the Truven MarketScan databases between 2009 and 2013. Demographic and treatment data were recorded, and over an 18-month follow-up period, the treatment cost was tallied. A log-transformed linear model was used to compare cost between the groups. RESULTS: A total of 2343 women were identified who met our inclusion criteria, with 1295 undergoing unilateral mastectomy and 1048 undergoing contralateral prophylactic mastectomy. Complication rates within 18 months were similar for women undergoing unilateral mastectomy and contralateral prophylactic mastectomy (39 percent versus 42 percent; p = 0.17). Management with unilateral mastectomy with reconstruction required an adjusted cumulative mean cost of $33,557. Contralateral prophylactic mastectomy with reconstruction was an additional $11,872 in expenditure (p < 0.001). The cost of initial procedures (mean difference, $6467) and secondary procedures (mean difference, $2455) were the greatest contributors to cost. CONCLUSIONS: In women with unilateral breast cancer, contralateral prophylactic mastectomy with reconstruction is more costly. The increased monetary cost of contralateral prophylactic mastectomy may be offset by improved quality of life. However, this financial reality is an important consideration when ongoing efforts toward reimbursement reform may not pay for contralateral prophylactic mastectomy if outcomes data are not presented to justify this procedure.

Partitioning of a polymer chain between a confining cavity and a gel.

A lattice field theory approach to the statistical mechanics of charged polymers in electrolyte solutions [S. Tsonchev, R. D. Coalson, and A. Duncan, Phys. Rev. E 60, 4257 (1999)] is applied to the study of a polymer chain contained in a spherical cavity but able to diffuse into a surrounding gel. The distribution of the polymer chain between the cavity and the gel is described by its partition coefficient, which is computed as a function of the number of monomers in the chain, the monomer charge, and the ion concentrations in the solution.

Designing Biodegradable PHA-Based 3D Scaffolds with Antibiofilm Properties for Wound Dressings: Optimization of the Microstructure/Nanostructure.

One major factor inhibiting natural wound-healing processes is infection through bacterial biofilms, particularly in the case of chronic wounds. In this study, the micro/nanostructure of a wound dressing was optimized in order to obtain a more efficient antibiofilm protein-release profile for biofilm inhibition and/or detachment. A 3D substrate was developed with asymmetric polyhydroxyalkanoate (PHA) membranes to entrap Dispersin B (DB), the antibiofilm protein. The membranes were prepared using wet-induced phase separation (WIPS). By modulating the concentration and the molecular weight of the porogen polymer, polyvinylpyrrolidone (PVP), asymmetric membranes with controlled porosity were obtained. PVP was added at 10, 30, and 50% w/w, relative to the total polymer concentration. The physical and kinetic properties of the quaternary nonsolvent/solvent/PHA/PVP systems were studied and correlated with the membrane structures obtained. The results show that at high molecular weight (Mw = 360 kDa) and high PVP content (above 30%), pore size decreased and the membrane became extremely brittle with serious loss of physical integrity. This brittle effect was not observed for low molecular weight PVP (Mw = 40 kDa) at comparable contents. Whatever the molecular weight, porogen content up to 30% increased membrane surface porosity and consequently protein uptake. Above 30% porogen content, the pore size and the physical integrity/mechanical robustness both decreased. The PHA membranes were loaded with DB and their antibiofilm activity was evaluated against Staphylococcus epidermidis biofilms. When the bacterial biofilms were exposed to the DB-loaded PHA membrane, up to 33% of the S. epidermidis biofilm formation was inhibited, while 26% of the biofilm already formed was destroyed. These promising results validate our approach based on the development of bioactive-protein-loaded asymmetric membranes for antibiofilm strategies in situations where traditional antibiotic therapies are ineffective.

Surface composition XPS analysis of a plasma treated polystyrene: Evolution over long storage periods.

A polystyrene surface (PS) was initially treated by cold nitrogen and oxygen plasma in order to incorporate in particular amine and hydroxyl functions, respectively. The evolution of the chemical nature of the surface was further monitored over a long time period (580 days) by chemical assay, XPS and contact angle measurements. Surface density quantification of primary amine groups was performed using three chemical amine assays: 4-nitrobenzaldehyde (4-NBZ), Sulfo succinimidyl 6-[3'(2 pyridyldithio)-pionamido] hexanoate (Sulfo-LC-SPDP) and iminothiolane (ITL). The results showed amine densities were in the range of 2 per square nanometer (comparable to the results described in the literature) after 5min of nitrogen plasma treatment. Over the time period investigated, chemical assays, XPS and contact angles suggest a drastic significant evolution of the chemical nature of the surface within the first two weeks. Beyond that time period and up to almost two years, nitrogen plasma modified substrates exhibits a slow and continuous oxidation whereas oxygen plasma modifed polystyrene surface is chemically stable after two weeks of storage. The latter appeared to "ease of" showing relatively mild changes within the one year period. Our results suggest that it may be preferable to wait for a chemical "stabilization" period of two weeks before subsequent covalent immobilization of proteins onto the surface. The originality of this work resides in the study of the plasma treated surface chemistry evolution over long periods of storage time (580 days) considerably exceeding those described in the literature.

Bioengineering and characterization of DNA-protein assemblies floating on supported membranes.

This chapter describes the design, practical construction, and characterization of P-DNA and their applications in building a new generation of DNA chips. P-DNAs are artificial covalent assemblies involving a histidine tag head able to bind to modified phospholipids, a core protein domain derived from cytochrome b5 by genetic engineering that features specific spectroscopic and electrochemical properties useful for detection, a synthetic linker acting as a spacer, and an oligonucleotide acting as a probe. P-DNA has the property of being able to efficiently self-associate to a supported bilayer including nickel-iminodiacetate-modified phospholipids. The construction of P-DNA and its interaction with a complementary oligonucleotide sequence can be monitored in real time by surface plasmon resonance using a Biacore system or equivalent. P-DNA chips feature unique properties including tunable surface density of probes; very low nonspecific interaction with external DNA; lateral mobility, minimizing-steric interaction; optimization of hybridization efficiency; and, potentially, recognition by multiple probes of a single target and perfectly defined and homogeneous structure, permitting high density up to a compact monolayer. Potential applications of this new device are multiple, including high-sensitivity and high-selectivity chips for DNA-DNA, DNA-RNA, or DNA-protein interactions.

Elucidation of innovative antibiofilm materials.

It is known for roughly a decade that bacterial communities (called biofilms) are responsible for significant enhanced antibiotherapy resistance. Biofilms are involved in tissue persistent infection, causing direct or collateral damage leading to chronic wounds development and impairing natural wound healing. In this study, we are interested in the development of supported protein materials which consist of asymmetric membranes as reservoir supports for the incorporation and controlled release of biomolecules capable of dissolving biofilms (or preventing their formation) and their use as wound dressing for chronic wound treatment. In a first step, polyhydroxyalkanoates (PHAs) asymmetric membranes were prepared using wet phase inversion technique. Scanning microscopy (SEM) analysis has showed the influence of different processing parameters. In a second step, the porous side of the membranes were functionalized with a surface treatment and then loaded with the antibiofilm agent (dispersin B). In a third step, the properties and antibiofilm performance of the loaded-membranes were evaluated. Exposure of Staphylococcus epidermidis biofilms to such systems weakly inhibited biofilm formation (weak preventive effect) but caused their detachment and disaggregation (strong curative effect). These initial results are promising since they open the way to a new generation of effective tools in the struggle against persistent bacterial infections exhibiting enhanced antibiotherapy resistance, and in particular in the case of infected chronic wounds.

Surface assembly on biofunctional magnetic nanobeads for the study of protein-ligand interactions.

One of the major challenges of proteomics today is to increase the power potential for the identification of as many proteins as possible and to characterize their interactions with specific free ligands (interactomics) or present on cell walls (cell marker), in order to obtain a global, integrated view of disease processes, cellular processes and networks at the protein level. The work presented here proposes the development of biofunctionalized magnetic nanobeads that might be used for interactomic investigations. The strategy consisted in immobilizing proteins via a non covalent technique that provides greater possibilities for the advent of faster, cheaper and highly miniaturizable protein analysis systems, in particular in situations where the amount of isolated protein is scarce (trace proteins). The advantage of the immobilization technique proposed here over more conventional covalent binding techniques is that it is versatile and universal (not protein specific) thus applicable to a wide range of proteins, in "mild" conditions that are non deleterious to the native structure and bioactivity of the immobilized protein. The feasibility of the technique was investigated using a model protein (streptavidin). The nanobeads were analyzed in size by light diffusion and transmission electronic spectroscopy, and in quantity of immobilized protein using a bioassay developed in the laboratory. Results are promising in that nanobeads exhibited good colloidal stability and surface concentrations in the monolayer range.