Houston founder shares how he's using tech to make digital media more effective and equitable

houston innovators podcast episode 173

This month, Mark Walker is celebrating his company's one year anniversary of going public — only the ninth Black-founded business to accomplish this feat on a U.S. stock exchange. Photo courtesy

After working in both sides of the advertising world, Mark Walker thought he could reimagine a platform that would be more efficient and equitable.

Walker co-founded his company, Direct Digital Holdings, an adtech platform, after serving in several roles — from an early hire at Houston digital media startup Questia to business development director at NRG Energy and COO of EBONY Media. He shares on the Houston Innovators Platform how he took this experience in tech, advertising, and media to create his company's platform.

"NRG Energy gave me a top-down view of the value chain, and Ebony gave me a bottoms-up view of the value chain of how media is purchased," Walker says on the show. "At Direct Digital Holdings, we help companies buy and sell media — and we leverage technology to do it. It's really the culmination of both of those experiences."

With over 30,000 publishers on its platform, Direct Digital makes it easier for its core customers — middle market companies looking to buy into the digital media ecosystem — to tap into these opportunities without the tech know-how they might otherwise need. Walker explains that at EBONY, he saw how small to midsize publications — especially the multicultural ones — were being left out on the ad selling side of the equation. The Direct Digital platform bridges the gap on each end.

Founded in 2018 in partnership with Keith Smith, who went through similar professional experiences, Direct Digital went public exactly one year ago after growing the company through strategic M&A activity. Walker says the decision to IPO made the most sense for his company — though it wasn't an easy process. Direct Digital is only the ninth company founded by a Black entrepreneur to go public on a US stock exchange.

"If you think the process is hard — it actually is," Walker says on the journey to IPO. "We were a privately held company, and we knew we had a good growth trajectory and we looked a couple different options. We decided to go public in a very traditional way."

Walker explains there were some risks involved, but the co-founders ultimately decided to shy away from adding in investors who might not have the same ideas for the company's future.

Direct Digital has been a Houston company from the star — despite the city not being home to a booming adtech ecosystem. Instead, Houston — with its collection of Fortune 500 companies and rich diversity — has allowed the business to stand out.

"If you look at and reflect on how our company has been built — from our board of directors to our leadership and management team — we're a majority minority organization all the way across the board," Walker says. "Diversity is very important to us. It's the lifeblood of our business — especially because we're serving publishers in those communities in big way. And moreso, we think you get the best product, thoughts, and ideas from a diverse workforce, and Houston fits right into that mold for us."

Walker shares more about his company's future, advice on IPO, and what all he's watching in adtech — from AI to streaming — on the podcast. Listen to the interview below — or wherever you stream your podcasts — and subscribe for weekly episodes.


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Houston startup debuts bio-based 'leather' fashion collection in Milan

sustainable fashion

Earlier this month, Houston-based Rheom Materials and India’s conscious design studio Econock unveiled a collaborative capsule collection that signaled more than just a product launch.

Hosted at Lineapelle—long considered the global epicenter of the world's premier leather supply chain—in the vaulted exhibition halls of Rho-Fiera Milano, the collection centered around Rheom’s 91 percent bio-based leather alternative, Shorai.

It was a bold move, one that shifted sustainability from a concept discussed in panel sessions to garments that buyers could touch and wear.

The collection featured a bomber-style jacket, an asymmetrical skirt and a suite of accessories—all fabricated from Shorai.

The standout piece, a sculptural jacket featuring a funnel neck and dual-zip closure, was designed for movement, challenging assumptions about performance limitations in bio-based materials. The design of the asymmetrical skirt was drawn from Indian armored warrior traditions, according to Rheom, with biodegradable corozo fasteners.

Built as a modular wardrobe rather than isolated pieces, the collection reflects a shared belief between Rheom and Econock in designing objects that adapt to daily life, according to the companies.

The collection was born out of a new partnership between Rheom and Econock, focused on bringing biobased materials to the market. According to Rheom, the partnership solves a problem that has stalled the adoption of many next-gen textiles: supply chain friction.

While Rheom focuses on engineering scalable bio-based materials, New Delhi-based Econock brings the complementary design and manufacturing ecosystem that integrates artisans, circular materials and production expertise to translate the innovative material into finished goods.

"This partnership removes one of the biggest barriers brands face when adopting next-generation materials,” Megan Beck, Rheom’s director of product, shared in a news release. “By reducing friction across the supply chain, Rheom can connect brands directly with manufacturers who already know how to work with Shorai, making the transition to more sustainable materials far more accessible.”

Sanyam Kapur, advisor of growth and impact at Econock, added: “Our partnership with Rheom Materials represents the benchmark of responsible design where next-gen materials meet craft, creativity, and real-world scalability.”

Rheom, formerly known as Bucha Bio, has developed Shorai, a sustainable leather alternative that can be used for apparel, accessories, car interiors and more; and Benree, an alternative to plastic without the carbon footprint. In 2025, Rheom was a finalist for Startup of the Year in the Houston Innovation Awards.

Shorai is already used by fashion lines like Wuxly and LuckyNelly, according to Rheom. The company scaled production of the sugar-based material last year and says it is now produced in rolls that brands can take to market with the right manufacturer.

Houston startup debuts leather alternative fashion collection in Milan

Houston clean energy co. secures $100M to deploy tech on global scale

Going Global

Houston-based Utility Global has raised $100 million in an ongoing Series D round to globally deploy its decarbonization technology at an industrial scale.

The round was led by Ara Partners and APG Asset, according to a news release. Utility plans to use the funding to expand manufacturing, grow its teams and support its commercial developments and partnerships.

“This financing marks a critical step in Utility’s transition from a proven technology to full-scale global commercial execution,” Parker Meeks, CEO and president of Utility Global, said in the release. “Industrial customers are no longer looking for pilots or promises; they need deployable solutions that work within existing assets and deliver true economic industrial decarbonization today that is operationally reliable and highly scalable. Utility’s technology produces both economic clean hydrogen and capture-ready CO2 streams, and this capital enables us to scale and deploy that impact globally with speed, discipline, and rigor.”

Utility Global's H2Gen technology produces low-cost, clean hydrogen from water and industrial off-gases without requiring electricity. It's designed to integrate into existing industrial infrastructure in hard-to-abate assets in the steel, refining, petrochemical, chemical, low-carbon fuels, and upstream oil and gas sectors.

“Utility is tackling one of the most difficult challenges in the energy transition: decarbonizing hard‑to‑abate industrial sectors,” Cory Steffek, partner at Ara Partners and Utility Global board chair, said in the release. “What sets Utility apart is its ability to compete head‑to‑head with conventional fossil‑based solutions on cost and reliability, even as it materially reduces emissions. With this new funding, Utility is well-positioned for its next chapter of commercial growth while maintaining the technical excellence and capital discipline that have defined its development to date.”

Utility Global reached several major milestones in 2025. After closing a $53 million Series C, the company agreed to develop at least one decarbonization facility at an ArcelorMittal steel plant in Brazil. It also signed a strategic partnership with California-based Kyocera International Inc. to scale global manufacturing of its H2Gen electrochemical cells.

The company also partnered with Maas Energy Works, another California company, to develop a commercial project integrating Maas’ dairy biogas systems with H2Gen to produce economical, clean hydrogen.

"These projects were never intended to stand alone. They anchor a deep and growing pipeline of commercial projects now in development globally across steel, refining, chemicals, biogas and other hard-to-abate sectors worldwide, Meeks shared in a 2025 year-in-review note. He added that 2026 would be a year of "focused acceleration to scale."

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This article originally appeared on EnergyCapitalHTX.com.

Houston Methodist awarded $4M grant to recruit head of Neal Cancer Center

new hire

Armed with a $4 million state grant, the Houston Methodist Academic Institute has recruited a renowned expert in ovarian and endometrial cancer research to lead the Dr. Mary and Ron Neal Cancer Center.

The grant, provided by the Cancer Prevention and Research Institute of Texas, enabled the institute to lure Dr. Daniela Matei away from Northwestern University’s Feinberg School of Medicine in Chicago. There, she is the Diana Princess of Wales Professor in Cancer Research and chief of the Division of Reproductive Science in Medicine.

Matei will succeed Dr. Jenny Chang, who was hired last year to run the Houston Methodist Academic Institute.

At the Neal Cancer Center, located in the Texas Medical Center complex, oncologists work on innovations in cancer research, treatment, and technology. The center opened in 2021 after the Neals donated $25 million to expand Houston Methodist’s cancer research capabilities. It handles about 7,000 new cases each year involving more than two dozen types of cancer.

U.S. News & World Report puts Houston Methodist Hospital at No. 19 among the country’s best hospitals for cancer care, two spots below Chicago’s Northwestern Memorial Hospital. The University of Texas MD Anderson Cancer Center in Houston sits at No. 1 on the list.

Matei’s research related to ovarian and endometrial cancer holds the potential to benefit tens of thousands of American women. The American Cancer Society estimates:

  • 21,010 women in the U.S. will be diagnosed with ovarian cancer, and 12,450 women will die from it.
  • 68,270 women in the U.S. will be diagnosed with endometrial cancer, and 14,450 women will die from it.

Matei is leaving Northwestern in the wake of widespread cuts in federal funding for medical research. The National Institutes of Health (NIH) has canceled or frozen tens of millions of dollars in grants for Northwestern, the Wall Street Journal reports, and the university has been plugging the gaps with its own money.

“The university is totally keeping us on life support,” Matei told the newspaper last year. “The big question is for how long they can do this.”

According to the Wall Street Journal, Matei’s $5 million NIH grant supporting 69 cancer trials has been caught up in the federal funding chaos, so Northwestern stepped in to cover trial expenses such as nurses’ salaries and diagnostic procedures.

Trial participants include some patients with rare, incurable tumors who are undergoing experimental treatments aligned with the genetics of their condition, the newspaper says.

“It’s certainly a life-and-death situation for cancer patients on these trials,” Matei said in 2025.

Matei is among the beneficiaries of more than $15 million in grants approved February 18 by CPRIT’s board. The grants went toward recruiting five cancer researchers to institutions in Texas.

One of those grants, totaling $1.5 million, went to the University of Houston to recruit Akash Gupta, a research scientist at MIT’s Koch Institute for Integrative Cancer Research. The remaining grants went to recruit scientists to The University of Texas at Dallas and The University of Texas Southwestern Medical Center.
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